From db0855dbeb41ecb8a51dde8587d43e5d7e83620f Mon Sep 17 00:00:00 2001
From: Thomas Stephen Lee
Date: Fri, 28 Aug 2015 16:53:23 +0530
Subject: add books

---
 .../chapter1.ipynb                                 |  62 +++
 .../chapter10.ipynb                                | 537 ++++++++++++++++++
 .../chapter11.ipynb                                |  61 +++
 .../chapter12.ipynb                                | 141 +++++
 .../chapter13.ipynb                                |  67 +++
 .../chapter14.ipynb                                | 300 +++++++++++
 .../chapter15.ipynb                                | 225 ++++++++
 .../chapter3.ipynb                                 | 598 +++++++++++++++++++++
 .../chapter4.ipynb                                 | 324 +++++++++++
 .../chapter6.ipynb                                 | 483 +++++++++++++++++
 .../chapter7.ipynb                                 | 252 +++++++++
 .../chapter8.ipynb                                 |  63 +++
 .../chapter9.ipynb                                 | 112 ++++
 .../screenshots/HPBW_FNBW_CH10.png                 | Bin 0 -> 90257 bytes
 .../screenshots/designValues_ch11.png              | Bin 0 -> 63595 bytes
 .../screenshots/gain_fnbw_hpbw.png                 | Bin 0 -> 70999 bytes
 16 files changed, 3225 insertions(+)
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter1.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter10.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter11.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter12.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter13.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter14.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter15.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter3.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter4.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter6.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter7.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter8.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/chapter9.ipynb
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/screenshots/HPBW_FNBW_CH10.png
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/screenshots/designValues_ch11.png
 create mode 100644 Antenna_and_Wave_Propagation_by_S._Wali/screenshots/gain_fnbw_hpbw.png

(limited to 'Antenna_and_Wave_Propagation_by_S._Wali')

diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter1.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter1.ipynb
new file mode 100644
index 00000000..b8295615
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter1.ipynb
@@ -0,0 +1,62 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:37d7c9e86e6a81ee7eb6a2dbfc73df70c3266a2471b35c7c536efad1cc61aa82"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter1, Review of Electromagnetics and Transmission Lines"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 1.1.1, page 1-3"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "f1=100 #kHz\n",
+      "f2=1 #MHz\n",
+      "f3=10 #MHz\n",
+      "c=3*10**8 #m/s\n",
+      "lamda1=c/(f1*10**3) #m\n",
+      "lamda2=c/(f2*10**6) #m\n",
+      "lamda3=c/(f3*10**6) #m\n",
+      "print \"At 100kHz, wavelength = %0.f km \" %(lamda1/1000) \n",
+      "print \"At 1MHz, wavelength = %0.f m \" %lamda2 \n",
+      "print \"At 10MHz, wavelength = %0.f m \"%lamda3"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "At 100kHz, wavelength = 3 km \n",
+        "At 1MHz, wavelength = 300 m \n",
+        "At 10MHz, wavelength = 30 m \n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter10.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter10.ipynb
new file mode 100644
index 00000000..7eaf93ee
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter10.ipynb
@@ -0,0 +1,537 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:3caeb5ca80f9060d923ecab5e68747215440e54b9d8723f23ecf08701ce3af01"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter10, Broadband & Frequency Independent Antenna"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.5.1, page : 10-16"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "from math import sqrt, atan, pi\n",
+      "N=5 #no. of turns\n",
+      "f=400 #MHz(Frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "print \"Part (i):\" \n",
+      "S=lamda/50 #m(Spacing between turns)\n",
+      "S_BY_lamda=1/50 #(Spacing/wavelength)\n",
+      "C_BY_lamda=sqrt(2*S_BY_lamda) #(Circumference/wavelength)\n",
+      "print \"\\tCircumference is\",C_BY_lamda,\"*lamda\" \n",
+      "C=sqrt(2*lamda*S) #m(Circumference)\n",
+      "print \"\\tCircumference = %0.2f meter \"%C \n",
+      "print \"Part (ii):\" \n",
+      "Lo_BY_lamda=sqrt(S_BY_lamda**2+C_BY_lamda**2) #(Length/wavelength)\n",
+      "print \"\\tLength of single turn is\",round(Lo_BY_lamda,6),\"*lamda\" \n",
+      "Lo=sqrt(S**2+C**2) #m(Length of single turn)\n",
+      "print \"\\tLength of single turn = %0.5f meter \"%Lo \n",
+      "print \"Part (iii):\" \n",
+      "Ln_BY_lamda=N*Lo_BY_lamda #(Overall length/wavelength)\n",
+      "print \"\\tOverall Length is\",round(Ln_BY_lamda,7),\"*lamda\" \n",
+      "Ln=N*Lo #m(Overall length)\n",
+      "print \"\\tOverall Length = %0.5f meter  \"%Ln \n",
+      "print \"Part (iv):\" \n",
+      "alfa=atan(S/C)*180/pi #degree(Pitch angle)\n",
+      "print \"\\tPitch angle, \u03b1 = %0.2f degree\"%alfa"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tCircumference is 0.2 *lamda\n",
+        "\tCircumference = 0.15 meter \n",
+        "Part (ii):\n",
+        "\tLength of single turn is 0.200998 *lamda\n",
+        "\tLength of single turn = 0.15075 meter \n",
+        "Part (iii):\n",
+        "\tOverall Length is 1.0049876 *lamda\n",
+        "\tOverall Length = 0.75374 meter  \n",
+        "Part (iv):\n",
+        "\tPitch angle, \u03b1 = 5.71 degree\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.5.2, page : 10-16"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi, sqrt, log10\n",
+      "from __future__ import division\n",
+      "N=5 #no. of turns\n",
+      "f=300 #MHz(Frequency)\n",
+      "c=3*10**8 #m/s(speed of light)\n",
+      "print \"Part (i):\" \n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "C_BY_lamda=1 #(Circumference/wavelength)\n",
+      "print \"\\tNear optimum circumference is\",C_BY_lamda,\"*lamda\" \n",
+      "C=lamda #m(Circumference)\n",
+      "print \"\\tNear optimum circumference = %0.f meter\" %C\n",
+      "print \"Part (ii):\" \n",
+      "alfa=14 #degree#(Pitch angle)#for near optimum\n",
+      "S_BY_lamda=C_BY_lamda*tan(alfa*pi/180) \n",
+      "print \"\\tSpacing is\",round(S_BY_lamda,4),\"*lamda\" \n",
+      "S=C*tan(alfa*pi/180) #m(Spacing)\n",
+      "print \"\\tSpacing = %0.4f meter \"%S \n",
+      "print \"Part (iii):\" \n",
+      "Rin=140*C/lamda #\u03a9(Input impedence)\n",
+      "print \"\\tInput impedence = %0.2f \u03a9 \"%Rin \n",
+      "print \"Part (iv):\" \n",
+      "HPBW=52/(C/lamda*sqrt(N*S/lamda)) #degree(HPBW)\n",
+      "print \"\\tHPBW = %0.2f degree \"%HPBW \n",
+      "print \"Part (v):\" \n",
+      "FNBW=115/(C/lamda*sqrt(N*S/lamda)) #degree(FNBW)\n",
+      "print \"\\tFNBW = %0.2f degree \" %FNBW \n",
+      "print \"Part (vi):\" \n",
+      "Do=15*(C/lamda)**2*N*(S/lamda) #unitless##Directivity\n",
+      "print \"\\tDirectivity(unitless) : %0.4f\"%Do \n",
+      "Do_dB=10*log10(Do) #dB(Directivity)\n",
+      "print \"\\tDirectivity = %0.3f dB \"%Do_dB \n",
+      "print \"Part (vii):\" \n",
+      "AR=(2*N+1)/2/N #axial ratio\n",
+      "print \"\\tAxial ratio : \",AR \n",
+      "print \"Part (viii):\" \n",
+      "Rin=140*(C/lamda) #\u03a9(Input impedence)\n",
+      "#50 \u03a9 line\n",
+      "Zo=50 #\u03a9(Output impedence)\n",
+      "Tau=(Rin-Zo)/(Rin+Zo) #Scaling factor\n",
+      "VSWR=(1+Tau)/(1-Tau) #(VSWR)\n",
+      "print \"\\tVSWR for 50\u03a9 line : \",VSWR \n",
+      "#75 \u03a9 line\n",
+      "Zo=75 #\u03a9(Output impedence)\n",
+      "Tau=(Rin-Zo)/(Rin+Zo) #Scaling factor\n",
+      "VSWR=(1+Tau)/(1-Tau) #(VSWR)\n",
+      "print \"\\tVSWR for 75\u03a9 line : %0.3f\"%VSWR "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tNear optimum circumference is 1 *lamda\n",
+        "\tNear optimum circumference = 1 meter\n",
+        "Part (ii):\n",
+        "\tSpacing is 0.2493 *lamda\n",
+        "\tSpacing = 0.2493 meter \n",
+        "Part (iii):\n",
+        "\tInput impedence = 140.00 \u03a9 \n",
+        "Part (iv):\n",
+        "\tHPBW = 46.57 degree \n",
+        "Part (v):\n",
+        "\tFNBW = 103.00 degree \n",
+        "Part (vi):\n",
+        "\tDirectivity(unitless) : 18.6996\n",
+        "\tDirectivity = 12.718 dB \n",
+        "Part (vii):\n",
+        "\tAxial ratio :  1.1\n",
+        "Part (viii):\n",
+        "\tVSWR for 50\u03a9 line :  2.8\n",
+        "\tVSWR for 75\u03a9 line : 1.867\n"
+       ]
+      }
+     ],
+     "prompt_number": 15
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.5.3, page : 10-18"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi, sqrt, log10\n",
+      "HPBW=39 #degree(HPBW)\n",
+      "alfa=12.5 #degree(Pitch angle)\n",
+      "f=475 #MHz(Frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "C=lamda #m(Circumference)\n",
+      "print \"Part (i):\" \n",
+      "#it is in axial mode as 3/4*lamda<C<4/3*lamda\n",
+      "S=C*tan(alfa*pi/180) #meter(Spacing)\n",
+      "N=52**2/HPBW**2/(S/lamda)/(C/lamda)**2 #turns\n",
+      "print \"\\tNumber of turns : \",round(N) \n",
+      "print \"Part (ii):\" \n",
+      "N=round(N) #turns\n",
+      "Do=15*(C/lamda)**2*N*(S/lamda) #unitless(Directivity)\n",
+      "Do_dB=10*log10(Do) #dB(Directivity)\n",
+      "print \"\\tDirectivity = %0.2f decibels\"%Do_dB \n",
+      "print \"Part (iii):\" \n",
+      "AR=(2*N+1)/2/N #axial ratio\n",
+      "print \"\\tAxial ratio : \",AR \n",
+      "print \"Part (iv):\" \n",
+      "#3/4*lamda<C<4/3*lamda\n",
+      "lamda1=C/(3/4) #meter(Wavelength)\n",
+      "lamda2=C/(4/3) #meter(Wavelength)\n",
+      "f1=c/lamda1 #Hz(Frequency)\n",
+      "f2=c/lamda2 #Hz(Frequency)\n",
+      "print \"\\tFrequency range is\",(f1/10**6),\"MHz to\",round(f2/10**6,2),\"MHz.\"\n",
+      "print \"Part (v):\" \n",
+      "#At  design frequency\n",
+      "Rin=140*C/lamda #\u03a9(Input impedence)\n",
+      "print \"\\tAt design frequency, Input impedence = %0.2f \u03a9  \"%Rin \n",
+      "#3/4*lamda<C<4/3*lamda\n",
+      "#At high frequency end\n",
+      "Rin=140*C/lamda2 #\u03a9(Input impedence)\n",
+      "print \"\\tAt high frequency end, Input impedence = %0.2f \u03a9 \"%Rin \n",
+      "#At low frequency end\n",
+      "Rin=140*C/lamda1 #\u03a9(Input impedence)\n",
+      "print \"\\tAt low frequency end, Input impedence = %0.2f \u03a9  \"%Rin "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tNumber of turns :  8.0\n",
+        "Part (ii):\n",
+        "\tDirectivity = 14.25 decibels\n",
+        "Part (iii):\n",
+        "\tAxial ratio :  1.0625\n",
+        "Part (iv):\n",
+        "\tFrequency range is 356.25 MHz to 633.33 MHz.\n",
+        "Part (v):\n",
+        "\tAt design frequency, Input impedence = 140.00 \u03a9  \n",
+        "\tAt high frequency end, Input impedence = 186.67 \u03a9 \n",
+        "\tAt low frequency end, Input impedence = 105.00 \u03a9  \n"
+       ]
+      }
+     ],
+     "prompt_number": 18
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.5.4, page : 10-20"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi, sqrt, log10\n",
+      "Do_dB=14 #dB(Directivity\n",
+      "f=2.4 #GHz(Frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Do=10**(Do_dB/10) #unitless(Directivity)\n",
+      "C=lamda #m##for optimum result(Circumference)\n",
+      "alfa=14 #degree ##for optimum result(Pitch angle)\n",
+      "S=C*tan(alfa*pi/180) #m(Spacing)\n",
+      "N=Do/15/(C/lamda)**2/(S/lamda) #turns\n",
+      "N=round(N) #turns\n",
+      "Rin=140*C/lamda #\u03a9(Input impedence)\n",
+      "print \"Input impedence = %0.2f \u03a9  \"%Rin \n",
+      "HPBW=52/(C/lamda*sqrt(N*S/lamda)) #degree\n",
+      "print \"HPBW = %0.2f degree \"%HPBW \n",
+      "FNBW=115/(C/lamda*sqrt(N*S/lamda)) #degree\n",
+      "print \"FNBW = %0.f degree \"%FNBW \n",
+      "AR=(2*N+1)/2/N #(Axial ratio)\n",
+      "print \"Axial ratio : \" ,round(AR,1)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Input impedence = 140.00 \u03a9  \n",
+        "HPBW = 39.36 degree \n",
+        "FNBW = 87 degree \n",
+        "Axial ratio :  1.1\n"
+       ]
+      }
+     ],
+     "prompt_number": 21
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.8.1, page : 10-36"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi, sqrt, log10, exp\n",
+      "f=10 #MHz(Frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "d0=10**-3*lamda #m(spacing)\n",
+      "Lo=1*lamda #m(Length)\n",
+      "fi=pi; fi0=0 #radian\n",
+      "r0=d0/2 #m\n",
+      "print \"Part (i):\" \n",
+      "#R=r0*exp(a*fi-a*fi0) #m\n",
+      "#a=sqrt(1/Lo**2/(R-r0)**2-1) #per adian\n",
+      "a=1.166 #rad**-1(by above equation)\n",
+      "print \"\\tRate of spiral = %0.3f rad^-1 \"%a \n",
+      "R_BY_lamda=r0/lamda*exp(a*2*pi) #m(Radius/wavelength)\n",
+      "print \"\\tRadius of terminal point is\",round(R_BY_lamda,5),\"*lamda\" \n",
+      "print \"Part (ii):\" \n",
+      "R=r0*exp(a*2*pi) #m(Radius)\n",
+      "print \"\\tRadius at terminal point = %0.2f meter \" %R "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tRate of spiral = 1.166 rad^-1 \n",
+        "\tRadius of terminal point is 0.75979 *lamda\n",
+        "Part (ii):\n",
+        "\tRadius at terminal point = 22.79 meter \n"
+       ]
+      }
+     ],
+     "prompt_number": 27
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.8.2, page : 10-37"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from fractions import Fraction\n",
+      "from math import tan, pi, sqrt, log, atan\n",
+      "fU=900 #MHz(Upper frequency)\n",
+      "fL=450 #MHz(Lower frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamdaU=c/(fU*10**6) #m(Upper wavelength)\n",
+      "lamdaL=c/(fL*10**6) #m(Lower wavelength)\n",
+      "Exp_ratio=4 #expansion ratio\n",
+      "a=log(Exp_ratio)/(2*pi) #rad**-1##rate of spiral\n",
+      "Beta=atan(1/a*pi/180) #degree\n",
+      "r0=lamdaU/4 #meter##minimum radius\n",
+      "print \"Minimum radius = %0.1f cm\"%(r0*100)   \n",
+      "R=lamdaL/4 #meter##minimum radius\n",
+      "print \"Maximum radius = %0.1f cm \"%(R*100) \n",
+      "fi_m=log(R/r0)/a #radian\n",
+      "fi_m=fi_m*180/pi #degree\n",
+      "print \"\u03a6m = %0.2f degree \"%(fi_m) \n",
+      "N=1/2 #for \u03a6m=180 #degree\n",
+      "print \"Number of turns, N is\",Fraction(N)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Minimum radius = 8.3 cm\n",
+        "Maximum radius = 16.7 cm \n",
+        "\u03a6m = 180.00 degree \n",
+        "Number of turns, N is 1/2\n"
+       ]
+      }
+     ],
+     "prompt_number": 34
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.10.1, page :10-49"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi, sqrt, log, atan\n",
+      "Gain=8.5 #dB(Gain)\n",
+      "tau=0.822;sigma=0.149 #for given gain\n",
+      "alfa=2*atan((1-tau*180/pi)/4/sigma) #degree\n",
+      "fL=54 #MHz(Lower frequency)\n",
+      "fU=216 #MHz(Upper frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamdaU=c/(fU*10**6) #m(Upper wavelength)\n",
+      "lamdaL=c/(fL*10**6) #m(Lower wavelength)\n",
+      "l1=lamdaU/2 #m(Length of element1)\n",
+      "lN=lamdaL/2 #m(Length of longest element)\n",
+      "l2=l1/tau; l3=l2/tau; l4=l3/tau; l5=l4/tau; l6=l5/tau; l7=l6/tau; l8=l7/tau; l9=l8/tau #m(Length of elements)\n",
+      "#Spacing between elements in meter\n",
+      "d1=2*sigma*l1 \n",
+      "d2=2*sigma*l2 \n",
+      "d3=2*sigma*l3 \n",
+      "d4=2*sigma*l4 \n",
+      "d5=2*sigma*l5 \n",
+      "d6=2*sigma*l6 \n",
+      "d7=2*sigma*l7 \n",
+      "d8=2*sigma*l8 \n",
+      "d9=2*sigma*l9 \n",
+      "d=d1+d2+d3+d4+d5+d6+d7+d8+d9 #meter(total spacing)\n",
+      "print \"Length of longest element = %0.2f m\"%lN \n",
+      "print \"Length of element1 = %0.3f m\"%l1\n",
+      "print \"Length of element1 = %0.3f m\"%l2\n",
+      "print \"Length of element1 = %0.3f m\"%l3\n",
+      "print \"Length of element1 = %0.3f m\"%l4\n",
+      "print \"Length of element1 = %0.3f m\"%l5\n",
+      "print \"Length of element1 = %0.3f m\"%l6\n",
+      "print \"Length of element1 = %0.3f m\"%l7\n",
+      "print \"Length of element1 = %0.3f m\"%l8\n",
+      "print \"Length of element1 = %0.3f m\\n\"%l9\n",
+      "print \"Spacing of element1 = %0.3f m\" %d1\n",
+      "print \"Spacing of element1 = %0.3f m\" %d2\n",
+      "print \"Spacing of element1 = %0.3f m\" %d3\n",
+      "print \"Spacing of element1 = %0.3f m\" %d4\n",
+      "print \"Spacing of element1 = %0.3f m\" %d5\n",
+      "print \"Spacing of element1 = %0.3f m\" %d6\n",
+      "print \"Spacing of element1 = %0.3f m\" %d7\n",
+      "print \"Spacing of element1 = %0.3f m\" %d8\n",
+      "print \"Spacing of element1 = %0.3f m\" %d9\n",
+      "print \"Total Spacing length = %0.3f m \"%d \n",
+      "#Answer is not accurate in the book."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Length of longest element = 2.78 m\n",
+        "Length of element1 = 0.694 m\n",
+        "Length of element1 = 0.845 m\n",
+        "Length of element1 = 1.028 m\n",
+        "Length of element1 = 1.250 m\n",
+        "Length of element1 = 1.521 m\n",
+        "Length of element1 = 1.850 m\n",
+        "Length of element1 = 2.251 m\n",
+        "Length of element1 = 2.739 m\n",
+        "Length of element1 = 3.332 m\n",
+        "\n",
+        "Spacing of element1 = 0.207 m\n",
+        "Spacing of element1 = 0.252 m\n",
+        "Spacing of element1 = 0.306 m\n",
+        "Spacing of element1 = 0.373 m\n",
+        "Spacing of element1 = 0.453 m\n",
+        "Spacing of element1 = 0.551 m\n",
+        "Spacing of element1 = 0.671 m\n",
+        "Spacing of element1 = 0.816 m\n",
+        "Spacing of element1 = 0.993 m\n",
+        "Total Spacing length = 4.622 m \n"
+       ]
+      }
+     ],
+     "prompt_number": 40
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 10.10.2, page : 10-52"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import tan, pi\n",
+      "from numpy import array\n",
+      "tau=0.895 #scale factor\n",
+      "sigma=0.166 #(spacing factor)\n",
+      "fU=30 #MHz(Upper frequency)\n",
+      "fL=10 #MHz(Lower frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamdaU=c/(fU*10**6) #m(Upper wavelength)\n",
+      "lamdaL=c/(fL*10**6) #m(Lower wavelength)\n",
+      "l1=lamdaU/2 #m(Length of shortest element)\n",
+      "print \"Length of shortest element, l1 = %0.2f meter \"%l1 \n",
+      "#Length of element in meter\n",
+      "l2=l1/tau; l3=l2/tau; l4=l3/tau; l4=l3/tau; l5=l4/tau; l6=l5/tau; l7=l6/tau; l8=l7/tau; l9=l8/tau;\n",
+      "l10=l9/tau; l11=l10/tau #\n",
+      "print \"\"\"Other elements length l2, l3, l4, l5, l6, l7, l8, l9, l10, l11 are :\n",
+      "%0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f meter respectively.\"\"\"%(l2,l3,l4,l5,l6,l7,l8,l9,l10,l11)\n",
+      "alfa=17.97 #degree(angle)\n",
+      "R1=(l1/2)/tan(alfa/2*pi/180) #m(Spacing between elements)\n",
+      "R2=R1/tau; R3=R2/tau; R4=R3/tau; R4=R3/tau; R5=R4/tau; R6=R5/tau; R7=R6/tau; R8=R7/tau; R9=R8/tau; R10=R9/tau; R11=R10/tau #m\n",
+      "print \"Spacing between elements R1, R2, R3, R4, R5, R6, R7, R8,R9, R10, R11 are : \"\n",
+      "print \"%0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f, %0.2f meter respectively.\"%(R1,R2,R3,R4,R5,R6,R7,R8,R9,R10,R11)\n",
+      "#Answer is not accurate in the book."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Length of shortest element, l1 = 5.00 meter \n",
+        "Other elements length l2, l3, l4, l5, l6, l7, l8, l9, l10, l11 are :\n",
+        "5.59, 6.24, 6.97, 7.79, 8.71, 9.73, 10.87, 12.14, 13.57, 15.16 meter respectively.\n",
+        "Spacing between elements R1, R2, R3, R4, R5, R6, R7, R8,R9, R10, R11 are : \n",
+        "15.81, 17.67, 19.74, 22.05, 24.64, 27.53, 30.76, 34.37, 38.40, 42.91, 47.94 meter respectively.\n"
+       ]
+      }
+     ],
+     "prompt_number": 53
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter11.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter11.ipynb
new file mode 100644
index 00000000..d4c2c36c
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter11.ipynb
@@ -0,0 +1,61 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:3b7be046ef74bb4eda8d19b127e9471df469da2a70e7c694126d716d811cee71"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter11, Microstrip Antennas"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 11.9.1, page : 11-18"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "from __future__ import division\n",
+      "fr=10 #GHz(center frequency)\n",
+      "fr=fr*10**9 #Hz(center frequency)\n",
+      "epsilon_r=10.2 #(constant)\n",
+      "h=0.127 #cm(height of sustrate)\n",
+      "c=3*10**10 #cm/s(Speed of light)\n",
+      "W=c/2/fr*sqrt(2/(epsilon_r+1)) #cm(Physical dimension)\n",
+      "epsilon_reff=(epsilon_r+1)/2+(epsilon_r-1)/2*(1+12*h/W)**(-1/2) #(effective constant)\n",
+      "delta_L=h*0.412*(epsilon_reff+0.3)*(W/h+0.264)/((epsilon_reff-0.258)*(W/h+0.8)) #cm(distance)\n",
+      "L=c/2/fr/sqrt(epsilon_reff)-2*delta_L #cm(distance)\n",
+      "print \"Design values of W & L are : %0.3f & %0.4f cm \"%(W,L) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Design values of W & L are : 0.634 & 0.4255 cm \n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter12.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter12.ipynb
new file mode 100644
index 00000000..794bdecd
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter12.ipynb
@@ -0,0 +1,141 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:4d6e811d421f337f1031f361be319cf058aca6316009f472b471c43a8dde51c6"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter12, Reflector Antennas"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 12.9.1, page : 12-21"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "from math import log10\n",
+      "D=2 #m(Diameter)\n",
+      "f=6000 #MHz(Frequency)\n",
+      "c=3*10**8 #m/s##speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "FNBW=140*lamda/D #degree\n",
+      "print \"First null beam width, FNBW = %0.1f degree \"%FNBW \n",
+      "GP=6*(D/lamda)**2 #unitless(Power gain)\n",
+      "GP_dB=10*log10(GP) #dB(Power gain)\n",
+      "print \"Power Gain = %0.2f dB\"%GP_dB\n",
+      "#Ans in the book is not accurate."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "First null beam width, FNBW = 3.5 degree \n",
+        "Power Gain = 39.82 dB\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 12.9.2, page : 12-22"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10, sqrt\n",
+      "\n",
+      "GP=1000 #unitless(Power gain)\n",
+      "lamda=10 #cm(Wavelength)\n",
+      "D=sqrt(GP/6)*(lamda/100) #m(Diameter)\n",
+      "print \"Diameter of mouth = %0.2f meter\" %D\n",
+      "HPBW=58*(lamda/100)/D #degree(HPBW)\n",
+      "print \"Half power beam width, HPBW = %0.2f degree\"%HPBW"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Diameter of mouth = 1.29 meter\n",
+        "Half power beam width, HPBW = 4.49 degree\n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 12.9.3, page : 12-22"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10, sqrt, pi\n",
+      "D=6 #meter(Diameter)\n",
+      "f=10 #GHz(Frequency)\n",
+      "c=3*10**8 #m/s##speed of light\n",
+      "lamda=c/(f*10**9) #m(Wavelength)\n",
+      "GP=6*(D/lamda)**2 #unitless(Power gain)\n",
+      "GP_dB=10*log10(GP) #dB(Power gain)\n",
+      "print \"Gain = %0.2f dB \"%GP_dB\n",
+      "FNBW=140*lamda/D #degree(FNBW)\n",
+      "print \"FNBW = %0.2f degree \"%FNBW \n",
+      "HPBW=58*lamda/D #degree(HPBW)\n",
+      "print \"HPBW = %0.2f degree \"%HPBW \n",
+      "K=0.65 #constant\n",
+      "Ao=K*pi/4*D**2 #m\u00b2(Capture area)\n",
+      "print \"Capture area = %0.2f m\u00b2 \"%Ao "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Gain = 53.80 dB \n",
+        "FNBW = 0.70 degree \n",
+        "HPBW = 0.29 degree \n",
+        "Capture area = 18.38 m\u00b2 \n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter13.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter13.ipynb
new file mode 100644
index 00000000..0e837c9f
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter13.ipynb
@@ -0,0 +1,67 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:f6d3766ede10d7f012eb8ad865bad8af32df466b5fa260a3ac4557604c5c1440"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter13, Antenna Measurement"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 13.4.1, page : 13-10"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10, pi\n",
+      "from __future__ import division\n",
+      "Pr1=0.0297/1000 #W(Recieved power)\n",
+      "Pr2=0.0471/1000 #W(Recieved power)\n",
+      "Pr3=0.0374/1000 #W(Recieved power)\n",
+      "Pt=1 #W(Transmitted power)\n",
+      "R=10 #m(Radius)\n",
+      "f=980 #MHz(Frequency)\n",
+      "f=f*10**6 #Hz(Frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/f #m(Wavelength)\n",
+      "A=20*log10(4*pi*R/lamda)+10*log10(Pr1/Pt) #(A=G1dB+G2dB)\n",
+      "B=20*log10(4*pi*R/lamda)+10*log10(Pr2/Pt) #(B=G1dB+G3dB)\n",
+      "C=20*log10(4*pi*R/lamda)+10*log10(Pr3/Pt) #(C=G2dB+G3dB)\n",
+      "G1dB=(A+B-C)/2 \n",
+      "G2dB=(A-B+C)/2 \n",
+      "G3dB=(-A+B+C)/2 \n",
+      "print \"Gain of antennas, G1db, G2dB & G3dB(in dB) are : %0.f, %0.f & %0.f\"%(round(G1dB),round(G2dB),round(G3dB))"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Gain of antennas, G1db, G2dB & G3dB(in dB) are : 4, 3 & 5\n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter14.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter14.ipynb
new file mode 100644
index 00000000..1b3a9c64
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter14.ipynb
@@ -0,0 +1,300 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:0174690c77909c04b196794e86400339cc9b848d5d1c10d76a582a253b10cfc2"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter14, ground Wave Propagation"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.6.1, page : 14-11"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10\n",
+      "d=36000 #km(height of satellite)\n",
+      "f=4000 #MHz(frequency)\n",
+      "GT=20 #dB(Transmitter gain)\n",
+      "GR=40 #dB(Reciever gain)\n",
+      "PT=200 #W(Transmitted power)\n",
+      "PT=10*log10(PT) #dB(Transmitted power)\n",
+      "print \"Part (i):\" \n",
+      "Ls=32.44+20*log10(f)+20*log10(d) #dB(Free space transmission loss)\n",
+      "print \"\\tFree space transmission loss = %0.2f dB \"%Ls \n",
+      "print \"Part (ii):\" \n",
+      "PT=200 #W(Transmitted power)\n",
+      "PT_dB=10*log10(PT) #dB(Transmitted power)\n",
+      "PR_dB=PT_dB+GT+GR-Ls #dB(Recieved power)\n",
+      "PR=10**(PR_dB/10) #W(Recieved power)\n",
+      "print \"\\tReceived power = %0.2f pW  \"%(PR*10**12)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tFree space transmission loss = 195.61 dB \n",
+        "Part (ii):\n",
+        "\tReceived power = 5.50 pW  \n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.6.2, page : 14-12"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10, sqrt, pi\n",
+      "\n",
+      "f=150 #MHz(frequency)\n",
+      "c=3*10**8 #m/s(speed of light)\n",
+      "GT=1.64 #dB(Transmitter gain)\n",
+      "PT=20 #W(Transmitted power)\n",
+      "d=50 #km(distance)\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "E=sqrt(30*GT*PT)/(d*1000) #V/m(emf induced)\n",
+      "le=lamda/pi #m(Effective length)\n",
+      "Voc=E*le #V/m(Open circuit voltage)\n",
+      "print \"Open circuit voltage = %0.2f micro Volt \"%(Voc*10**6) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Open circuit voltage = 399.40 micro Volt \n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.1, page : 14-24"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10, sqrt, pi\n",
+      "\n",
+      "ht=100 #m(transmitter height)\n",
+      "hr=100 #m(receiver height)\n",
+      "d=3.57*(sqrt(ht)+sqrt(hr)) #km(Range)\n",
+      "print \"Range of space wave propagation = %0.2f km \"%d "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Range of space wave propagation = 71.40 km \n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.2, page : 14-27"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt, pi\n",
+      "\n",
+      "ht=100 #feet(transmitter height)\n",
+      "hr=50 #feet(receiver height)\n",
+      "d=1.4142*(sqrt(ht)+sqrt(hr)) #miles(Range)\n",
+      "print \"Radio horizon = %0.2f miles \"%d "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radio horizon = 24.14 miles \n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.3, page : 14-28"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "ht=80 #m(transmitter height)\n",
+      "hr=50 #m(receiver height)\n",
+      "d=4.12*(sqrt(ht)+sqrt(hr)) #km(Range)\n",
+      "print \"Maximum distance = %0.2f km  \"%d "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Maximum distance = 65.98 km  \n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.4, page : 14-28"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "ht=100 #m(transmitter height)\n",
+      "d=80 #km(receiver height)\n",
+      "hr=(d/4.12-sqrt(ht))**2 #m(range)\n",
+      "print \"Required height of receiving antenna = %0.2f meter \"%hr "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Required height of receiving antenna = 88.69 meter \n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.5, page : 14-28"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "ht=100 #m(transmitter height)\n",
+      "d=4.12*sqrt(ht) #km(Horizon distance)\n",
+      "print \"Horizon distance = %0.2f km \"%d "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Horizon distance = 41.20 km \n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 14.10.6, page : 14-36"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "P=35 #W(Transmitter power\n",
+      "ht=45 #m(transmitter height)\n",
+      "hr=25 #m(receiver height)\n",
+      "f=90 #MHz(frequency)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "d=4.12*(sqrt(ht)+sqrt(hr)) #km(line of sight distance)\n",
+      "print \"Distance of line of sight communication = %0.2f km  \"%d \n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "ER=88*sqrt(P)*ht*hr/(lamda*(d*1000)**2) #V/m(Field strength)\n",
+      "print \"Field strength = %0.2f micro Volt/meter \"%(ER*10**6) \n",
+      "#Answer is wrong in the textbook."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Distance of line of sight communication = 48.24 km  \n",
+        "Field strength = 83.90 micro Volt/meter \n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter15.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter15.ipynb
new file mode 100644
index 00000000..9281ffe2
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter15.ipynb
@@ -0,0 +1,225 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:f6acbba448e01b02069f788ecb787623745617a1524961607409e2c2ace0469f"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter15, Ionospheric Propagation"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.8.1, page : 15-19"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "fc_E=2.5 #MHz(critical frequency of E-layer)\n",
+      "fc_F=8.4 #MHz(critical frequency of F-layer)\n",
+      "print \"For E-layer : \" \n",
+      "Nm=(fc_E*10**6)**2/81 #per m**3(Maximum electron density)\n",
+      "print \"Maximum electron density = %0.4e per m**3 \"%Nm \n",
+      "print \"For F-layer : \" \n",
+      "Nm=(fc_F*10**6)**2/81 #per m**3(Maximum electron density)\n",
+      "print \"Maximum electron density = %0.4e per m**3 \"%Nm \n"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "For E-layer : \n",
+        "Maximum electron density = 7.7160e+10 per m**3 \n",
+        "For F-layer : \n",
+        "Maximum electron density = 8.7111e+11 per m**3 \n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.8.2, page : 15-19"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "Nm_D=400 #electron/cm**3(Maximum electron density)\n",
+      "Nm_E=5*10**5 #electron/cm**3(Maximum electron density)\n",
+      "Nm_F=2*10**6 #electron/cm**3(Maximum electron density)\n",
+      "fc_D=9*sqrt(Nm_D) #kHz(critical frequency of D-layer)\n",
+      "print \"Critical frequency for D-layer = %.2f kHz \"%fc_D \n",
+      "fc_E=9*sqrt(Nm_E) #kHz(critical frequency of E-layer)\n",
+      "print \"Critical frequency for E-layer = %0.3f MHz  \"%(fc_E/1000)\n",
+      "fc_F=9*sqrt(Nm_F) #kHz(critical frequency of F-layer)\n",
+      "print \"Critical frequency for F-layer = %0.1f MHz \"%(fc_F/1000) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Critical frequency for D-layer = 180.00 kHz \n",
+        "Critical frequency for E-layer = 6.364 MHz  \n",
+        "Critical frequency for F-layer = 12.7 MHz \n"
+       ]
+      }
+     ],
+     "prompt_number": 6
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.8.3, page : 15-19"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "Eta=0.5 #(refractive index)\n",
+      "N=400 #electron/cm**3(Electron density)\n",
+      "f=sqrt(81*N/(1-Eta**2)) #kHz(frequency)\n",
+      "print \"Frequency = %0.2f kHz \" %f "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Frequency = 207.85 kHz \n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.9.1, page : 15-22"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "T=5 #milli-seconds(time period)\n",
+      "c=3*10**8 #m/s#/speed of light\n",
+      "H=1.0/2*c*T*10**-3 #m(Virtual height)\n",
+      "print \"Virtual height = %0.2e km  \" %(H/1000) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Virtual height = 7.50E+02 km  \n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.12.1, page : 15-26"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "d=2000 #km\n",
+      "H=200 #km\n",
+      "fc=6 #MHz\n",
+      "f_MUF=fc*sqrt(1+(d/2/H)**2) #MHz\n",
+      "print \"MUF = %0.3f MHz \" %f_MUF "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "MUF = 30.594 MHz \n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 15.13.1, page : 15-29"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "Eta=0.9 #refractive index\n",
+      "f_MUF=10 #MHz\n",
+      "H=400 #km\n",
+      "Nm=(1-Eta**2)*(f_MUF*10**6)**2/81 #per m**3\n",
+      "fc=9*sqrt(Nm) #Hz\n",
+      "Dskip=2*H*sqrt((f_MUF*10**6/fc)**2-1) #km\n",
+      "print \"Skip distance or range = %0.2f km \" %Dskip "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Skip distance or range = 1651.79 km \n"
+       ]
+      }
+     ],
+     "prompt_number": 17
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter3.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter3.ipynb
new file mode 100644
index 00000000..79b1eca0
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter3.ipynb
@@ -0,0 +1,598 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:d9216abaea55a671c8710ff5277d260ca9c6b9e6c9e1a5aa7567e0769b212b24"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter3, Fundamental Parameters of Antenna"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.3.1, page 3-9"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt, acos, degrees\n",
+      "E_theta=1/sqrt(2) #Electric Field at half power\n",
+      "#theta=thetaHP/2 #E(thetaHP/2)=cosd(thetaHP/2)\n",
+      "thetaHP=2*degrees(acos(E_theta)) #degree(Half power beam width)\n",
+      "print \"Half power beam width = %0.2f degree \"%thetaHP "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Half power beam width = 90.00 degree \n"
+       ]
+      }
+     ],
+     "prompt_number": 1
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.3.2, page 3-10"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import asin, degrees\n",
+      "E_theta=1/sqrt(2) #Electric field at theta=90-thetaHP/2\n",
+      "#E(90-thetaHP/2)=sind(90-thetaHP/2)\n",
+      "thetaHP=2*(90-degrees(asin(E_theta)) )#degree(HPBW)\n",
+      "print \"HPBW = %0.2f degree \"%(thetaHP) \n",
+      "theta1=0 ;theta2=180 #degree(Pattern angles)\n",
+      "FNBW=theta2-theta1 #degree(FNBW)#as E is zero at these points\n",
+      "print \"FNBW = %0.2f degree \"%FNBW "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "HPBW = 90.00 degree \n",
+        "FNBW = 180.00 degree \n"
+       ]
+      }
+     ],
+     "prompt_number": 2
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.3.3, page 3-10"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import acos, degrees\n",
+      "E_theta=1/sqrt(2) #Elecric field at half power point\n",
+      "#E(thetaHP/2)=(cosd(thetaHP/2))**2\n",
+      "thetaHP=2*degrees(acos(sqrt(E_theta))) #degree(HPBW)\n",
+      "print \"Half Power Beam Width = %0.2f degree \"%thetaHP "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Half Power Beam Width = 65.53 degree \n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.8.1, page 3-23"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "from math import pi, cos, acos\n",
+      "theta1=0 ;theta2=pi/2 #radian(Angles)\n",
+      "fi1=0 ;fi2=2*pi #radian(Angles)\n",
+      "#Prad=integrate('integrate('U','thheta',theta1,theta2)','fi',fi1,fi2) \n",
+      "Prad_BY_Um=pi*(1/2)*(cos(2*theta1)-cos(2*theta2)) #(Power radiated/Max intensity)\n",
+      "Do=4*pi/Prad_BY_Um #Exact Directivity\n",
+      "print \"Exact Directivity : \",Do \n",
+      "#Um*Cosd(thetaHP/2)=0.5*Um\n",
+      "thetaHP=2*(degrees(acos(0.5))) #degree(HPBW)\n",
+      "fiHP=thetaHP #degree(HPBW)\n",
+      "Do=41253/(thetaHP*fiHP) #Approximate Directivity\n",
+      "print \"Approximate Directivity : \",round(Do,3)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Exact Directivity :  4.0\n",
+        "Approximate Directivity :  2.865\n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.10.1, page 3-26"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "K=90 #%#radiation efficiency\n",
+      "Pin=10 #W\n",
+      "Prad=(K/100)*Pin #W\n",
+      "print \"Radiated power = %0.f Watts \" %Prad "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radiated power = 9 Watts \n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.11.1, page 3-28"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10\n",
+      "D=20 #Directivity\n",
+      "K=90 #%#radiation efficiency\n",
+      "G=(K/100)*D #Gain\n",
+      "GdB=10*log10(G) #dB\n",
+      "print \"Gain = %0.2f dB \"%(GdB) \n",
+      "#Answer is not calculated in the book."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Gain = 12.55 dB \n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.11.2, page 3-29"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import log10\n",
+      "Rr=72 #\u03a9\n",
+      "RL=8 #\u03a9\n",
+      "G=16 #Gain\n",
+      "K=Rr/(Rr+RL)*100 #%#radiation efficiency\n",
+      "D=G/(K/100) #Directivity\n",
+      "DdB=10*log10(D) #dB\n",
+      "print \"Directivity = %0.3f dB\" %DdB"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Directivity = 12.499 dB\n"
+       ]
+      }
+     ],
+     "prompt_number": 10
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.13.1, page 3-35"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "Irms=15 #A(Current Drawn)\n",
+      "Prad=5 #kW(Radiated Power)\n",
+      "Rr=Prad*10**3/Irms**2 #\u03a9(Radiation Resistance)\n",
+      "print \"Radiation resistance = %0.2f \u03a9  \"%Rr"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radiation resistance = 22.22 \u03a9  \n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.13.2, page 3-35"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt\n",
+      "Prad=1000 #W(Radiated Power)\n",
+      "Rr=300 #\u03a9(Radiation Resistance)\n",
+      "Irms=sqrt(Prad/Rr) #A(Current Drawn)\n",
+      "print \"Current drawn = %0.1f A \"%Irms "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Current drawn = 1.8 A \n"
+       ]
+      }
+     ],
+     "prompt_number": 13
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.13.3, page 3-35"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "Rr=73 #\u03a9(Radiation Resistance)\n",
+      "Z=120*pi #\u03a9(For free space)\n",
+      "#le=lambda/pi\n",
+      "AemBYlambda_sqr=(1/pi)**2*Z/(4*Rr) \n",
+      "print \"Maximum effective aperture is \",round(AemBYlambda_sqr,2),\"*lambda\u00b2 m\u00b2\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Maximum effective aperture is  0.13 *lambda\u00b2 m\u00b2\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.13.4, page 3-35"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "Rr=73 #\u03a9\n",
+      "Z=120*pi #\u03a9(For free space)\n",
+      "#Aem=0.13*lambda\u00b2\n",
+      "AemBylambda_sqr=0.13 \n",
+      "leBYlambda=2*sqrt(AemBylambda_sqr*Rr)/sqrt(Z) \n",
+      "print \"Effective length is \",round(leBYlambda,4),\"*lambda meter\" "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Effective length is  0.3173 *lambda meter\n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.15.1, page 3-39"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt, log10\n",
+      "cos_si_p=1/sqrt(2) \n",
+      "PLF=cos_si_p**2 #Polarization Loss factor\n",
+      "PLFdB=10*log10(PLF) #dB\n",
+      "print \"Power loss factor = %0.f dB \"%PLFdB "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power loss factor = -3 dB \n"
+       ]
+      }
+     ],
+     "prompt_number": 18
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.16.1, page 3-43"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "Do_dB=20 #dB\n",
+      "f=10 #GHz\n",
+      "Wi=2*10**-3 #W/m\u00b2\n",
+      "c=3*10**8 #m/s\n",
+      "lamda=c/(f*10**9) #m\n",
+      "Do=10**(Do_dB/10) #unitless\n",
+      "Aem=lamda**2/(4*pi)*Do #m\u00b2\n",
+      "print \"Maximum effective aperture = %0.3e m\u00b2\" %Aem \n",
+      "Pr=Aem*Wi #W\n",
+      "print \"Maximum received power = %0.3f \u00b5W \"%(Pr*10**6) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Maximum effective aperture = 7.162e-03 m\u00b2\n",
+        "Maximum received power = 14.324 \u00b5W \n"
+       ]
+      }
+     ],
+     "prompt_number": 20
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.16.2, page 3-43"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "ecd=1.0 #for lossless antenna\n",
+      "Aem=2.147 #m\u00b2(Maximum Effective aperture)\n",
+      "Zin=75.0 #\u03a9(Input impedence)\n",
+      "Zo=50.0 #\u03a9(Output impedence)\n",
+      "f=100.0 #MHz(Operating frequency)\n",
+      "c=3*10**8 #m/s(speed f light)\n",
+      "aw_aa=1.0 #For no polarization loss\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Tau=(Zin-Zo)/(Zin+Zo) #(Reflection Coefficient)\n",
+      "Do=Aem/(ecd*(1.0-Tau**2)*lamda**2.0/(4*pi)/aw_aa**2) #unitless(Directivity)\n",
+      "print \"Directivity of antenna\",round(Do,3)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Directivity of antenna 3.123\n"
+       ]
+      }
+     ],
+     "prompt_number": 25
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.17.1, page 3-46"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "PT=15 #W(Transmitted Power)\n",
+      "AeT=0.2 #m\u00b2(Effective aperture)\n",
+      "AeR=0.5 #m\u00b2(Effective aperture)\n",
+      "f=5 #GHz(frequency)\n",
+      "r=15 #km(line of sight distance)\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**9) #m(Wavelength)\n",
+      "PR=PT*AeT*AeR/((r*1000)**2*lamda**2) #Watts(Power delivered to reciever)\n",
+      "print \"Power delivered to receiver = %0.2e Watts \"%(PR) \n",
+      "#Answer is wrong in the book. lambda is 0.6 instead of 0.06 and lambda**2 is 0.06 instead of 0.0036"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power delivered to receiver = 1.85e-06 Watts \n"
+       ]
+      }
+     ],
+     "prompt_number": 26
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.17.2, page 3-46"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "DT=20 #dB(Transmitter Directivity)\n",
+      "DR=20 #dB(Reciever Directivity)\n",
+      "PT=10 #W(Transmitted Power)\n",
+      "ecdT=1; ecdR=1 #(For lossless antenna)\n",
+      "aT_aR=1 #(For polarization match)\n",
+      "DT=10**(DT/10) #unitless(Transmitter Directivity)\n",
+      "DR=10**(DR/10) #unitless(Reciever Directivity)\n",
+      "Tau_T=0; Tau_R=0 #(Reflection coefficient)\n",
+      "rBYlambda=50 #m\n",
+      "PR=PT*ecdT*ecdR*(1-Tau_T**2)*(1-Tau_R**2)/(4*pi*rBYlambda)**2*DT*DR*aT_aR**2 #Watts(Power delivered to reciever)\n",
+      "print \"Power at receiving antenna = %0.3f Watts \"%PR  "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power at receiving antenna = 0.253 Watts \n"
+       ]
+      }
+     ],
+     "prompt_number": 28
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 3.17.3, page 3-47"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "f=3 #GHz\n",
+      "c=3*10**8 #m/s(Speed of light)\n",
+      "lamda=c/(f*10**9) #m(wavelength)\n",
+      "r=500 #m(distance)\n",
+      "PT=100 #W(Transmitted Power)\n",
+      "GT=25 #dB(Transmitter Gain)\n",
+      "GR=20 #dB(Reciever Gain)\n",
+      "GT=10**(GT/10) #unitless(Transmitter Gain)\n",
+      "GR=10**(GR/10) #unitless(Reciever Gain)\n",
+      "PLF=1; aT_aR=1 #(For polarization match)\n",
+      "PR=PT*(lamda/4/pi/r)**2*GT*GR*aT_aR**2 #Watts(Power delivered to reciever)\n",
+      "print \"Power delivered to load = %0.2e Watts \"%PR "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power delivered to load = 8.01e-04 Watts \n"
+       ]
+      }
+     ],
+     "prompt_number": 29
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter4.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter4.ipynb
new file mode 100644
index 00000000..d64c52dd
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter4.ipynb
@@ -0,0 +1,324 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:7ee429170e048ea291cb04ea69be8064a04800ea636a7a3699d6be07a58fc7ae"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter4, Linear Wire Antennas"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.2.1, page 4-17"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi, acos, degrees, cos, sin, atan\n",
+      "import numpy as np\n",
+      "l=5 #cm(length of antenna)\n",
+      "f=100 #MHz(operating frequency)\n",
+      "Io=120 #mA(Terminal current)\n",
+      "t=1 #s(time)\n",
+      "theta=45 #degree(Angle)\n",
+      "r=3 #m(radius)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "omega=2*pi*f*10**6 #rad/sec(rotation)\n",
+      "k=omega/c #rad/m(Phase constant)\n",
+      "kr=2*pi*r/3 #degree(Phase constant)\n",
+      "Er=Io*10**-3*l*10**-2/(2*pi*r**2)*cos(theta*pi/180)*120*pi*(1+1/(1J*kr))*np.exp(-1J*kr+1J*omega*t) #V/m(Electric field)\n",
+      "Er=Er*1000 #mV/m(Electric field)\n",
+      "Er_mag=abs(Er) #mV/m(magnitude of Er)\n",
+      "Er_angle=degrees(atan(Er.imag/Er.real)) #degree(angle of Er)\n",
+      "print \"Value of Er : magnitude = %0.2f mV/m & angle = %0.2f degree \" %(Er_mag,Er_angle) \n",
+      "Etheta=Io*10**-3*l*10**-2/(4*pi*r)*sin(theta*pi/180)*120*pi*1J*k*(1+1/(1J*kr)+1/(1J*kr)**2)*np.exp(-1J*kr+1J*omega*t) #V/m(Electric field)\n",
+      "Etheta_mag=abs(Etheta) #V/m(magnitude of Etheta)\n",
+      "Etheta_angle=degrees(atan(Etheta.imag/Etheta.real)) #degree(angle of Etheta)\n",
+      "print \"Value of Etheta : magnitude = %0.2e V/m & angle = %0.2f degree \" %(Etheta_mag,Etheta_angle) \n",
+      "Hfi=Io*10**-3*l*10**-2/(4*pi*r)*sin(theta*pi/180)*1J*k*(1+1/(1J*kr))*np.exp(-1J*kr+1J*omega*t) #A/m(Magnetic field)\n",
+      "Hfi_mag=abs(Hfi) #A/m(magnitude of Hfi)\n",
+      "Hfi_angle=degrees(atan(Hfi.imag/Hfi.real)) #degree(angle of Hfi)\n",
+      "print \"Value of H\u03a6 : magnitude = %0.3e A/m & angle = %0.f degree \" %(Hfi_mag,Hfi_angle) \n",
+      "#Answer is not accurate in the book."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Value of Er : magnitude = 28.64 mV/m & angle = -9.04 degree \n",
+        "Value of Etheta : magnitude = 8.78e-02 V/m & angle = 80.73 degree \n",
+        "Value of H\u03a6 : magnitude = 2.387e-04 A/m & angle = 81 degree \n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.5.1, page 4-35"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "f=500.0 #MHz(Operating Frequency)\n",
+      "Do=1.643 #for half wave dipole\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Aem=lamda**2/(4*pi)*Do #m\u00b2(Effective area)\n",
+      "print \"Effective area = %0.3f m\u00b2 \" %Aem "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Effective area = 0.047 m\u00b2 \n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.6.1, page 4-37"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt, pi\n",
+      "l=1 #m\n",
+      "Prad=4 #W\n",
+      "f=1.5 #MHz\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m\n",
+      "#here l/lamda<1/50 tells us it is a Hertzian monopole antenna\n",
+      "h=1 #m\n",
+      "Rr=40*pi**2*(h/lamda)**2 #m\u03a9\n",
+      "Io=sqrt(2*Prad/Rr) #A\n",
+      "print \"Current required = %0.2f A \" %Io "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Current required = 28.47 A \n"
+       ]
+      }
+     ],
+     "prompt_number": 5
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.9.1, page 4-51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "le=100.0 #m\n",
+      "Irms=450.0 #A\n",
+      "f=40000.0 #Hz\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/f #m\n",
+      "P=160*pi**2*(le/lamda)**2*Irms**2 #mW\n",
+      "Rr=160*pi**2*(le/lamda)**2 #\u03a9\n",
+      "print \"Power radiated = %0.2f kW \" %(P*10**-3) \n",
+      "print \"Radiation resistance = %0.3f \u03a9 \"%Rr\n",
+      "#Answer wrong for radiation resistance in the book."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power radiated = 56.85 kW \n",
+        "Radiation resistance = 0.281 \u03a9 \n"
+       ]
+      }
+     ],
+     "prompt_number": 8
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.9.2, page 4-51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "\n",
+      "le=61.4 #m\n",
+      "Irms=50 #A\n",
+      "lamda=625 #m\n",
+      "P=160*pi**2*(le/lamda)**2*Irms**2 #kW\n",
+      "Rr=160*pi**2*(le/lamda)**2 #\u03a9\n",
+      "print \"Power radiated = %0.2f kW \" %(P*10**-3) \n",
+      "print \"Radiation resistance = %0.2f \u03a9 \"%Rr "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Power radiated = 38.10 kW \n",
+        "Radiation resistance = 15.24 \u03a9 \n"
+       ]
+      }
+     ],
+     "prompt_number": 9
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.9.3, page 4-51"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "le=10.0 #m(effective length)\n",
+      "Irms=450 #A(rms current)\n",
+      "Rl=1.5 #\u03a9(resistance)\n",
+      "f=50.0 #kHz(Operating frequency)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**3) #m(Wavelength)\n",
+      "P=160*pi**2*(le/lamda)**2*Irms**2 #kW(Power)\n",
+      "P=P*1000 #W(Power)\n",
+      "Rr=160*pi**2*(le/lamda)**2 #\u03a9(Radiation resistance)\n",
+      "Eta=Rr/(Rr+Rl)*100 #%(Efficiency)\n",
+      "print \"Efficiency of antenna = %0.2f %% \"%Eta "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Efficiency of antenna = 0.29 % \n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.9.4, page 4-52"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "#l=lamda/8\n",
+      "lBYlamda=1.0/8 #(length/Wavelength)\n",
+      "Rr=80*pi**2*(lBYlamda)**2 #\u03a9(Radiation resistance)\n",
+      "print \"Radiation resistance = %0.4f \u03a9 \"%Rr "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radiation resistance = 12.3370 \u03a9 \n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 4.9.5, page 4-52"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "from math import pi\n",
+      "L=1 #m(Length of element)\n",
+      "f=10 #MHz(Operating frequency)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Rr=80*pi**2*(L/lamda)**2 #\u03a9(Radiation resistance)\n",
+      "print \"Radiation resistance = %0.3f \u03a9 \"%Rr "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radiation resistance = 0.877 \u03a9 \n"
+       ]
+      }
+     ],
+     "prompt_number": 16
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter6.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter6.ipynb
new file mode 100644
index 00000000..0debea51
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter6.ipynb
@@ -0,0 +1,483 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:e5e51717065f48c86dca50bb80c877a8dccdac1a1049a8aa680cfb5df955894e"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter6, Antenna Arrays"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.2.1, page 6-13"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "n=2 #(No. of point source)\n",
+      "#E=E0*{exp(%i*pi/2)-exp(-%i*si/2)} where exp(-%i*si)=-1\n",
+      "#si=Beta*d*cosd(fi)=2*pi*cosd(fi)\n",
+      "#E=2*%i*E0*sind(pi*cosd(fi))  But 2*%i*E0=1\n",
+      "from numpy import arange, sin, pi, cos, nditer\n",
+      "fi=arange(0,331,30) #degree(angle)\n",
+      "En=sin(pi*cos(fi*pi/180)) #Normalized field\n",
+      "print \" fi  :\\t\",\n",
+      "for x in fi:\n",
+      "    print x,\"\\t\",\n",
+      "print \"\"\n",
+      "print \"|En| :\\t\",\n",
+      "for x in abs(En):\n",
+      "    print \"%0.2f\"%x,\"\\t\","
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        " fi  :\t0 \t30 \t60 \t90 \t120 \t150 \t180 \t210 \t240 \t270 \t300 \t330 \t\n",
+        "|En| :\t0.00 \t0.41 \t1.00 \t0.00 \t1.00 \t0.41 \t0.00 \t0.41 \t1.00 \t0.00 \t1.00 \t0.41 \t"
+       ]
+      }
+     ],
+     "prompt_number": 31
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.2.2, page 6-16"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "n=2 #(No. of point source)\n",
+      "#E=E0*{exp(%i*(pi/4+si/2))-exp(-%i*(pi/4+si/2))} as exp(%i*theta)+exp(-%i*theta)=2*cos(theta)\n",
+      "#E=2*E0*cos(pi/4+si/2) \n",
+      "#si=Beta*d*cosd(fi)=2*pi*cosd(fi)\n",
+      "#En=cos(pi/4+Beta*d*cosd(pi/4))  But 2*E0=1\n",
+      "from numpy import arange, sin, pi, cos, nditer\n",
+      "fi=arange(0,331,30) #degree(angle)\n",
+      "En=cos(pi/4+pi/4*cos(fi*pi/180)) #Normalized field\n",
+      "print \" fi  :\\t\",\n",
+      "for x in fi:\n",
+      "    print x,\"\\t\",\n",
+      "print \"\"\n",
+      "print \"|En| :\\t\",\n",
+      "for x in abs(En):\n",
+      "    print \"%0.3f\"%x,\"\\t\","
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        " fi  :\t0 \t30 \t60 \t90 \t120 \t150 \t180 \t210 \t240 \t270 \t300 \t330 \t\n",
+        "|En| :\t0.000 \t0.105 \t0.383 \t0.707 \t0.924 \t0.994 \t1.000 \t0.994 \t0.924 \t0.707 \t0.383 \t0.105 \t"
+       ]
+      }
+     ],
+     "prompt_number": 36
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.2.3, page 6-18"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "#E=cos(fi)+sin(fi)<si \n",
+      "#En=cos(pi/4+pi*cosd(fi)) as 2*E0=1\n",
+      "from numpy import arange, sin, pi, cos, nditer\n",
+      "fi=arange(0,331,30) #degree(angle)\n",
+      "si=pi/2*(cos(fi*pi/180)+1) #(Phase)\n",
+      "En=cos(pi/4+pi*cos(fi*pi/180)) #Normalized field\n",
+      "print \" fi  :\\t\",\n",
+      "for x in fi:\n",
+      "    print x,\"\\t\",\n",
+      "print \"\"\n",
+      "print \"|En| :\\t\",\n",
+      "for x in abs(En):\n",
+      "    print \"%0.3f\"%x,\"\\t\",\n",
+      "#Answer in the book is wrong."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        " fi  :\t0 \t30 \t60 \t90 \t120 \t150 \t180 \t210 \t240 \t270 \t300 \t330 \t\n",
+        "|En| :\t0.707 \t0.934 \t0.707 \t0.707 \t0.707 \t0.356 \t0.707 \t0.356 \t0.707 \t0.707 \t0.707 \t0.934 \t"
+       ]
+      }
+     ],
+     "prompt_number": 39
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.6.1, page 6-34"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import degrees, acos\n",
+      "n=80.0 #(no. of elements)\n",
+      "N=1.0 #for first null\n",
+      "#d=lamda/2 (spacing)\n",
+      "dBYlamda=1.0/2 #(spacing/wavelength)\n",
+      "fi01=degrees(acos(N/n/dBYlamda)) #degree(Angle)\n",
+      "Null_1st=(pi/2*180/pi)-fi01 #degree(First Null)\n",
+      "print \"Location of 1st null from maxima = %0.2f degree \"%Null_1st "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Location of 1st null from maxima = 1.43 degree \n"
+       ]
+      }
+     ],
+     "prompt_number": 47
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example 6.6.2, page 6-34"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import degrees, acos\n",
+      "import numpy as np\n",
+      "n=4.0 #(No. of elements)\n",
+      "#d=lamda/2 (Spacing)\n",
+      "dBYlamda=1.0/2 #(Spacing/wavelength)\n",
+      "alfa=0 #degree(angle)\n",
+      "N=1.0 #(For first null)\n",
+      "print \"Part (i) :\" \n",
+      "theta01=np.array([degrees(acos(+N/2)),degrees(acos(-N/2))]) #degree(Angle)\n",
+      "N=2 #(For second null)\n",
+      "theta02=np.array([degrees(acos(+N/2)), degrees(acos(-N/2))]) #degree(angle)\n",
+      "#N=3 #not possible as N/2 is greater than 1\n",
+      "print \"\\tNull directions for N=1 : theta01 =\" ,theta01 ,\"degree\"\n",
+      "print \"\\tNull directions for N=2 : theta02 =\" ,theta02 ,\"degree\"\n",
+      "print \"Part (ii):\" \n",
+      "m=0 #for maxima\n",
+      "theta_m=degrees(acos(m/dBYlamda)) #degree(angle)\n",
+      "print \"\\tDirection of maxima : theta_m = %0.2f degree \" %theta_m\n",
+      "print \"Part (iii):\" \n",
+      "S=1 #for side lobe maxima\n",
+      "#S=2 & onwards not possible\n",
+      "theta_S=np.array([degrees(acos((2*S+1)/2/n/dBYlamda)), degrees(acos(-(2*S+1)/2/n/dBYlamda))]) #degree(angle for side lobe)\n",
+      "print \"\\tSide lobe maxima : theta_S =\",theta_S ,\"degree \"\n",
+      "print \"Part (iv):\" \n",
+      "HPBW=2*(90-degrees(acos(1.391/np.pi/n/dBYlamda))) #degree(HPBW)\n",
+      "print \"\\tHPBW = %0.2f degree \" %HPBW \n",
+      "print \"Part (v):\" \n",
+      "FNBW=2*(90-degrees(acos(1/n/dBYlamda))) #degree(FNBW)\n",
+      "print \"\\tFNBW = %0.2f degree \"%FNBW \n",
+      "print \"Part (vi):\" \n",
+      "SLL=-13.46 #dB##for isotropic sources array(Side lobe level)\n",
+      "print \"\\tSide lobe level = %0.2f dB \"%SLL \n",
+      "# Answer wrong in the textbook."
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i) :\n",
+        "\tNull directions for N=1 : theta01 = [  60.  120.] degree\n",
+        "\tNull directions for N=2 : theta02 = [   0.  180.] degree\n",
+        "Part (ii):\n",
+        "\tDirection of maxima : theta_m = 90.00 degree \n",
+        "Part (iii):\n",
+        "\tSide lobe maxima : theta_S = [  60.  180.] degree \n",
+        "Part (iv):\n",
+        "\tHPBW = 25.58 degree \n",
+        "Part (v):\n",
+        "\tFNBW = 60.00 degree \n",
+        "Part (vi):\n",
+        "\tSide lobe level = -13.46 dB \n"
+       ]
+      }
+     ],
+     "prompt_number": 21
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.8.1, page 6-41"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import numpy as np\n",
+      "from __future__ import division\n",
+      "n=4 #(No. of elements)\n",
+      "#d=lamda/2 (spacing)\n",
+      "dBYlamda=1/2 #(spacing/wavelength)\n",
+      "theta=0 #degree(angle)\n",
+      "#Beta=2*pi/lamda\n",
+      "print \"Part (i):\" \n",
+      "Beta_into_lamda=2*np.pi #(Coefficient)\n",
+      "#alfa=-Beta*d\n",
+      "alfa=-Beta_into_lamda*dBYlamda #radian(Progressive phase shift)\n",
+      "alfa=alfa*180/np.pi #degree(Progressive phase shift)\n",
+      "print \"\\tProgressive phase shift = %0.2f degree \"%alfa \n",
+      "print \"Part (ii):\" \n",
+      "N=range(1,4) #as N=4 is not allowed\n",
+      "theta01=degrees(acos(1-N[0]/n/dBYlamda)) #degree(angle)\n",
+      "theta02=degrees(acos(1-N[1]/n/dBYlamda)) #degree(angle)\n",
+      "theta03=degrees(acos(1-N[2]/n/dBYlamda)) #degree(angle)\n",
+      "print \"\\tNull directions, theta01, theta02 & theta03 are %0.2f, %0.2f & %0.2f degree \"%(theta01,theta02,theta03) \n",
+      "print \"Part (iii):\" \n",
+      "m=range(0,2) #as m=2 & onwards is not allowed\n",
+      "theta0=degrees(acos(1-m[0]/dBYlamda)) #degree(angle)\n",
+      "theta1=degrees(acos(1-m[1]/dBYlamda)) #degree(angle)\n",
+      "print \"\\tMaxima directions, theta0, theta1 are %0.2f & %0.2f degree \"%(theta0,theta1) \n",
+      "print \"Part (iv):\" \n",
+      "FNBW=2*degrees(acos(1-1/n/dBYlamda)) #degree(FNBW)\n",
+      "print \"\\tFNBW = %0.2f degree \"%(FNBW) \n",
+      "print \"Part (v):\" \n",
+      "HPBW=2*degrees(acos(1-1.391/n/np.pi/dBYlamda)) #degree(HPBW)\n",
+      "print \"\\tHPBW = %0.2f degree :  \"%HPBW "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Part (i):\n",
+        "\tProgressive phase shift = -180.00 degree \n",
+        "Part (ii):\n",
+        "\tNull directions, theta01, theta02 & theta03 are 60.00, 90.00 & 120.00 degree \n",
+        "Part (iii):\n",
+        "\tMaxima directions, theta0, theta1 are 0.00 & 180.00 degree \n",
+        "Part (iv):\n",
+        "\tFNBW = 120.00 degree \n",
+        "Part (v):\n",
+        "\tHPBW = 77.73 degree :  \n"
+       ]
+      }
+     ],
+     "prompt_number": 29
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.8.2, page 6-43"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "n=16 #no. of point source\n",
+      "#d=lamda/4 (spacing)\n",
+      "dBYlamda=1/4 #(Spacing/wavelength)\n",
+      "HPBW=2*degrees(acos(1-1.391/n/np.pi/dBYlamda)) #degree(HPBW)\n",
+      "print \"HPBW = %0.2f degree\" %HPBW"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "HPBW = 54.43 degree\n"
+       ]
+      }
+     ],
+     "prompt_number": 31
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.10.1, page 6-50"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "n=10 #no. of elements\n",
+      "#d=lamda/4 (spacing)\n",
+      "dBYlamda=1/4 #/(Spacing/wavelength)\n",
+      "#Broadside array\n",
+      "D=2*n*dBYlamda #unitless(Directivity)\n",
+      "D=10*np.log10(D) #dB(Directivity)\n",
+      "print \"Directivity for broadside array = %0.2f dB \" %D\n",
+      "#Endfire array\n",
+      "D=4*n*dBYlamda #unitless(Directivity)\n",
+      "D=10*np.log10(D) #dB(Directivity)\n",
+      "print \"Directivity for Ordinary endfire array = %0.2f dB \"%D "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Directivity for broadside array = 6.99 dB \n",
+        "Directivity for Ordinary endfire array = 10.00 dB \n"
+       ]
+      }
+     ],
+     "prompt_number": 33
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.10.2, page 6-50"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "D=20 #dB(Directivity)\n",
+      "#d=lamda/4 (spacing)\n",
+      "dBYlamda=1/4 #(spacing/wavelength)\n",
+      "D=10**(D/10) #unitless(Directivity)\n",
+      "n=D/4/dBYlamda #no. of elements\n",
+      "print \"(i) No. of elements : \",n \n",
+      "LBYlamda=(n-1)*dBYlamda #(length/wavelength)\n",
+      "print \"(ii) Length of the array is \",(LBYlamda),\"*lamda\" \n",
+      "HPBW=2*degrees(acos(1-1.391/np.pi/n/dBYlamda)) #degree(HPBW)\n",
+      "print \"(iii) HPBW = %0.2f degree \" %HPBW \n",
+      "SLL=-13.46 #dB(Side lobe level)\n",
+      "print \"(iv) SLL = %0.2f dB \" %SLL \n",
+      "Beta_into_lamda=2*np.pi #(temorary calculatuion)\n",
+      "#alfa=-Beta*d #for theta=0\n",
+      "#alfa=Beta*d #for theta=180\n",
+      "alfa1=-Beta_into_lamda*dBYlamda #radian##for theta=0\n",
+      "alfa1=alfa1*180/np.pi #degree(angle)\n",
+      "alfa2=Beta_into_lamda*dBYlamda #radian##for theta=180\n",
+      "alfa2=alfa2*180/np.pi #degree(angle)\n",
+      "print \"(v) Progressive phase shift, \u03b1 for theta equals to 0\u00b0 & 180\u00b0 are : \",(alfa1,alfa2) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "(i) No. of elements :  100.0\n",
+        "(ii) Length of the array is  24.75 *lamda\n",
+        "(iii) HPBW = 21.60 degree \n",
+        "(iv) SLL = -13.46 dB \n",
+        "(v) Progressive phase shift, \u03b1 for theta equals to 0\u00b0 & 180\u00b0 are :  (-90.0, 90.0)\n"
+       ]
+      }
+     ],
+     "prompt_number": 40
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 6.14.1, page 6-74"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from sympy import symbols, solve\n",
+      "SLL=19.1 #dB(Side Lobe Level)\n",
+      "#d=lamda/2 (spacing)\n",
+      "dBYlamda=1/2 #(Spacing/wavelength)\n",
+      "n=4 #(no. of elements)\n",
+      "r=round(10**(SLL/20)) #(ratio of main lobe to side lobe)\n",
+      "m=n-1 #(degree )\n",
+      "x0 = symbols('x0')\n",
+      "#T3(x0)=r=4*x0**3-3*x0 \n",
+      "T3=4*x0**3-3*x0 -9\n",
+      "#x0=roots([4 0 -3 -r]) #(Coefficient)\n",
+      "x0=solve(T3)\n",
+      "x0=x0[0] #taking real value(Coefficient)\n",
+      "#E4(z)=T3(x)=4*x**3-3*x=4*a1*z**3-3*a1*z+a0*z\n",
+      "#4*a1*z**3=4*x**3 where z**3=(x/x0)**3\n",
+      "a1=4*x0**3/4 #(Coefficient)\n",
+      "#a0*z-3*z*a1=-3*x\n",
+      "a0=(3/x0*a1-3)*x0 #(Coefficient)\n",
+      "print \"Coefficients of array polynomial a1 & a0 are : \",float(a0),\"&\", float(a1)\n",
+      "print \"Relative current amplitudes are :\",round(float(a0/a1),2),\"&\",float(a1/a1)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Coefficients of array polynomial a1 & a0 are :  5.625 & 3.375\n",
+        "Relative current amplitudes are : 1.67 & 1.0\n"
+       ]
+      }
+     ],
+     "prompt_number": 52
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter7.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter7.ipynb
new file mode 100644
index 00000000..38d43a85
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter7.ipynb
@@ -0,0 +1,252 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:8165b8e5dad1d709dff36c0fb8461bb25ed06730a63d035a743672c074cb35cf"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter07, Loop Antenna"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.1, page : 7-16"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import numpy as np\n",
+      "A=1 #m\u00b2(Area of loop)\n",
+      "N=400 #no. of turns\n",
+      "Q=100 #Quality factor\n",
+      "theta=60 #degree(angle)\n",
+      "Erms=10 #\u00b5V/m(field strength)\n",
+      "f=1 #MHz(tuned frequency)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Vr=Q*2*np.pi*A*N*np.cos(theta*np.pi/180)*Erms*10**-6/lamda #V(reciever input voltage)\n",
+      "print \"Input voltage to the receiver = %0.3f mV  \" %(Vr*1000)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Input voltage to the receiver = 4.189 mV  \n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.2, page : 7-17"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "import numpy as np\n",
+      "N=12 #no. of turns\n",
+      "A=1 #m\u00b2(Area of loop)\n",
+      "Erms=100 #\u00b5V/m(field strength)\n",
+      "f=10 #MHz(tuned frequency)\n",
+      "theta=0 #degree(angle)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "Vr=2*np.pi*A*N*np.cos(theta*np.pi/180)*Erms*10**-6/lamda #V(reciever input voltage)\n",
+      "print \"Voltage induced in loop = %0.2f \u00b5V/m \" %(Vr*10**6) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Voltage induced in loop = 251.33 \u00b5V/m \n"
+       ]
+      }
+     ],
+     "prompt_number": 4
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.3, page : 7-17"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "N=25 #no. of turns\n",
+      "Vrms=150 #\u00b5V(emf induced)\n",
+      "f=500 #kHz(tuned frequency)\n",
+      "A=0.5**2 #m\u00b2(Area of loop)\n",
+      "theta=0 #degree(angle)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**3) #m(Wavelength)\n",
+      "Erms=lamda/(2*np.pi*A*N*np.cos(theta*np.pi/180))*Vrms*10**-6 #V/m(maximum emf induced)\n",
+      "print \"Field strength = %0.3f mV/m  \"%(Erms*10**3) "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Field strength = 2.292 mV/m  \n"
+       ]
+      }
+     ],
+     "prompt_number": 7
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.4, page : 7-17"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "N1=1.0 #no. of turns in primary\n",
+      "N2=8.0 #no. of turns in secondary\n",
+      "#a=lamda/25 \n",
+      "aBYlamda=1.0/25 #(temporary calculation)\n",
+      "#A=np.pi*a**2\n",
+      "A_BY_lamda_sqr=np.pi*aBYlamda**2 #(temporary calculation)\n",
+      "Rr1=31200*(N1*A_BY_lamda_sqr)**2 #\u03a9(Radiation resistance for single turn)\n",
+      "print \"Radiation resistance for single turn loop = %0.4f \u03a9 \" %(Rr1) \n",
+      "Rr2=31200*(N2*A_BY_lamda_sqr)**2 #\u03a9(Radiation resistance for 8 turn)\n",
+      "print \"Radiation resistance for 8 turn loop = %0.2f \u03a9 \" %Rr2 "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Radiation resistance for single turn loop = 0.7883 \u03a9 \n",
+        "Radiation resistance for 8 turn loop = 50.45 \u03a9 \n"
+       ]
+      }
+     ],
+     "prompt_number": 11
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.5, page : 7-18"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "f=100 #MHz(Operating frequency)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(Wavelength)\n",
+      "a=lamda/25 #m(radius)\n",
+      "C=2*np.pi*a #m(Circumference)\n",
+      "d=2*10**-4*lamda #m(Spacing)\n",
+      "print \"For single turn : \" \n",
+      "N=1 #n. of turns\n",
+      "RL_BY_Rr=3430.0/(C**3*f**(3.5)*N*d) #(temporary calculation)\n",
+      "K=1/(1+RL_BY_Rr)*100 #%(Radiation efficiency)\n",
+      "print \"Radiation efficiency of single turn = %0.2f %%\" %K\n",
+      "print \"For Eight turn : \" \n",
+      "N=8 #no. of turns\n",
+      "RL_BY_Rr=3430/(C**3*f**(3.5)*N*d) #(temporary calculation)\n",
+      "K=1/(1+RL_BY_Rr)*100 #%(Radiation efficiency)\n",
+      "print \"Radiation efficiency of eight turn = %0.2f %%\" % K"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "For single turn : \n",
+        "Radiation efficiency of single turn = 42.85 %\n",
+        "For Eight turn : \n",
+        "Radiation efficiency of eight turn = 85.71 %\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 7.10.6, page : 7-19"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from fractions import Fraction\n",
+      "a=0.5 #m(radius)\n",
+      "f=0.9 #MHz(OPerating frequency)\n",
+      "c=3*10**8 #m/s##Speed of light\n",
+      "lamda=c/(f*10**6) #m(wavelength)\n",
+      "C=2*np.pi*a #m(Circumference)\n",
+      "if C/lamda<1/3:\n",
+      "    D=3/2 #Directivity\n",
+      "elif C/lamda>1/3:\n",
+      "    D=0.682*C/lamda #Directivity\n",
+      "\n",
+      "print \"Directivity :\" ,Fraction(D)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Directivity : 3/2\n"
+       ]
+      }
+     ],
+     "prompt_number": 18
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter8.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter8.ipynb
new file mode 100644
index 00000000..8916d228
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter8.ipynb
@@ -0,0 +1,63 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:6e71dd92d1b17d959b3f4a36646e163cb828dba9f629a380a86a078783aa8586"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter8, Slot Antenna"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 8.3.1, page : 8-3"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import pi\n",
+      "import numpy as np\n",
+      "Zcs=73+1J*42.5 #\u00ce\u00a9(Impedence of complementry structure)\n",
+      "Eta=120*pi #(Constant for free space)\n",
+      "ZS=Eta**2/4/Zcs #\u00ce\u00a9(Input Impedence)\n",
+      "print \"Input impedence =\",np.around(ZS),\"ohm\"\n",
+      "#At resonance\n",
+      "Zcs=73 #\u00ce\u00a9(Impedence of complementry structure)\n",
+      "Eta=120*pi #(Constant for free space)\n",
+      "ZS=Eta**2/4/Zcs #\u00ce\u00a9(Input Impedence)\n",
+      "print \"At resonance, Input impedence = %0.2f ohm\"%ZS\n",
+      "print \"ZS can be rounded to 500 \u00ce\u00a9\""
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Input impedence = (364-212j) ohm\n",
+        "At resonance, Input impedence = 486.72 ohm\n",
+        "ZS can be rounded to 500 \u00ce\u00a9\n"
+       ]
+      }
+     ],
+     "prompt_number": 21
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
diff --git a/Antenna_and_Wave_Propagation_by_S._Wali/chapter9.ipynb b/Antenna_and_Wave_Propagation_by_S._Wali/chapter9.ipynb
new file mode 100644
index 00000000..fa219e98
--- /dev/null
+++ b/Antenna_and_Wave_Propagation_by_S._Wali/chapter9.ipynb
@@ -0,0 +1,112 @@
+{
+ "metadata": {
+  "name": "",
+  "signature": "sha256:a1c5dc80edceb1c26296c5ed290e825905396ed6d9e62f8196824c971236a909"
+ },
+ "nbformat": 3,
+ "nbformat_minor": 0,
+ "worksheets": [
+  {
+   "cells": [
+    {
+     "cell_type": "heading",
+     "level": 1,
+     "metadata": {},
+     "source": [
+      "Chapter09, Horn Antenna"
+     ]
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 9.6.1, page : 9-8"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from __future__ import division\n",
+      "f=2 #GHz(Frequency)\n",
+      "G=12 #dBi(Gain)\n",
+      "D=12 #dBi(Gain)\n",
+      "D=10**(D/10) #unitless(Directivity)\n",
+      "c=3*10**8 #m/s(speed of light)\n",
+      "lamda=c/(f*10**9) #m(wavelength)\n",
+      "Ap=D*lamda**2/7.5 #m\u00b2(capture area)\n",
+      "print \"Required capture area = %0.4f m\u00b2 \"%Ap "
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Required capture area = 0.0475 m\u00b2 \n"
+       ]
+      }
+     ],
+     "prompt_number": 3
+    },
+    {
+     "cell_type": "heading",
+     "level": 2,
+     "metadata": {},
+     "source": [
+      "Example No. 9.6.2, page : 9-9"
+     ]
+    },
+    {
+     "cell_type": "code",
+     "collapsed": false,
+     "input": [
+      "from math import sqrt, atan, pi, log10\n",
+      "aEBYlamda=10 #(Aperture/wavelength)\n",
+      "del_EBYlamda=0.2 #in E-plane\n",
+      "del_HBYlamda=0.375 #in H-plane\n",
+      "LBYlamda=aEBYlamda**2/8/del_EBYlamda #(Length/wavelength)\n",
+      "print \"Length of the horn is \",(LBYlamda),\"*lamda\" \n",
+      "aHBYlamda=sqrt(LBYlamda*8*del_HBYlamda) #(Aperture/wavelength)\n",
+      "print \"H-plane aperture, aH is \",round(aHBYlamda,2),\"*lamda\" \n",
+      "theta_E=2*atan(aEBYlamda/2/LBYlamda)*180/pi #degree(Angle)\n",
+      "theta_H=2*atan(aHBYlamda/2/LBYlamda)*180/pi #degree(Angle)\n",
+      "print \"Flare angles theta_E & theta_H = %0.2f & %0.2f degree \"%(theta_E,theta_H) \n",
+      "HPBW_E=56/aEBYlamda #degree(HPBW for E-plane)\n",
+      "print \"HPBW(E-plane) = %0.1f degree\"%(HPBW_E) \n",
+      "HPBW_H=67/aHBYlamda #degree(HPBW for H-plane)\n",
+      "print \"HPBW(H-plane) = %0.1f degree \" %HPBW_H \n",
+      "FNBW_E=102/aEBYlamda #degree(FNBW for E-plane)\n",
+      "print \"FNBW(E-plane) = %0.2f degree \" %FNBW_E \n",
+      "FNBW_H=172/aHBYlamda #degree(FNBW for F-plane)\n",
+      "print \"FNBW(H-plane) = %0.2f degree \"%FNBW_H \n",
+      "D=10*log10(7.5*aEBYlamda*aHBYlamda) #(Directivity)\n",
+      "print \"Directivity in dB  : \", round(D,2)"
+     ],
+     "language": "python",
+     "metadata": {},
+     "outputs": [
+      {
+       "output_type": "stream",
+       "stream": "stdout",
+       "text": [
+        "Length of the horn is  62.5 *lamda\n",
+        "H-plane aperture, aH is  13.69 *lamda\n",
+        "Flare angles theta_E & theta_H = 9.15 & 12.50 degree \n",
+        "HPBW(E-plane) = 5.6 degree\n",
+        "HPBW(H-plane) = 4.9 degree \n",
+        "FNBW(E-plane) = 10.20 degree \n",
+        "FNBW(H-plane) = 12.56 degree \n",
+        "Directivity in dB  :  30.12\n"
+       ]
+      }
+     ],
+     "prompt_number": 14
+    }
+   ],
+   "metadata": {}
+  }
+ ]
+}
\ No newline at end of file
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-- 
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