{ "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": {} } ] }