{ "metadata": { "name": "", "signature": "sha256:55fa86de219c4f643fa6676095f34a4af682ba335d02a01747382a5f3a074890" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2 : Basic Principles in Radiowave Propagation" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.1, page 25" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "\n", "#Initialisation\n", "sig=0.005 #sigma\n", "ur=1 #relative permeability\n", "er=12 #relative permittivity\n", "eo=8.85*10**-12 #permittivity of a free space\n", "f1=10*10**3 #frequency of radio wave 1\n", "f2=10*10**9 #frequency of radio wave 2\n", "\n", "#Calculation\n", "c1=sig/(2*math.pi*f1*eo*er) #conductivity at f1\n", "c2=sig/(2*math.pi*f2*eo*er) #conductivity at f2\n", "\n", "\n", "#Result\n", "print'conductivity at f1 = %.1f >> 1'%c1\n", "print'conductivity at f2 = %.1f x10^-4 >> 1'%(c2*10**4)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "conductivity at f1 = 749.3 >> 1\n", "conductivity at f2 = 7.5 x10^-4 >> 1\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.2, page 26" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "c1=3*10**8 #speed of light in m/s\n", "f1=100*10**6 #frequency in hertz\n", "f2=1*10**9 #frequency in hertz\n", "\n", "#Calculation\n", "v1=c1/(9) #velocity in m/s\n", "v2=c1 #velocity in m/s\n", "h1=v1*f1**-1 #wavelength at f1, v1\n", "h2=v2*f1**-1 #wavelength at f1, v2\n", "h3=v1*f2**-1 #wavelength at f2, v1\n", "h4=v2*f2**-1 #wavelength at f2, v2\n", "\n", "#Result\n", "print'Velocity,'\n", "print'V1 = %.2f x10^7 m/s'%(v1*10**-7)\n", "print'V2 = %.2f x10^8 m/s'%(v2*10**-8)\n", "print'\\nfor f1 = 100 MHz'\n", "print'lambda1 = %f m'%h1\n", "print'lambda2 = %d m'%h2\n", "print'\\nfor f2 = 1 GHz'\n", "print'lambda1 = %.2f cm'%(h3*10)\n", "print'lambda2 = %d cm'%(h4*10**2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Velocity,\n", "V1 = 3.33 x10^7 m/s\n", "V2 = 3.00 x10^8 m/s\n", "\n", "for f1 = 100 MHz\n", "lambda1 = 0.333333 m\n", "lambda2 = 3 m\n", "\n", "for f2 = 1 GHz\n", "lambda1 = 0.33 cm\n", "lambda2 = 30 cm\n" ] } ], "prompt_number": 40 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.3, page 37" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "import cmath\n", "\n", "#Initialisation\n", "s=0.08 #medium conductivit\n", "w=10**7 #angular velocity\n", "e=8.85*10**-7 #permitivity if free space\n", "u=14 #medium permeability\n", "uo=4*3.14*10**-7 #permeability of free space\n", "\n", "#Calculation\n", "f=w*(2*3.14)**-1 #frequency\n", "a=math.sqrt(f*math.pi*s*uo) #attenuation\n", "b=a #phase\n", "d=complex(a,b)\n", "y=d #propagation constants\n", "z=math.log10(0.5)/(-math.log10(math.exp(1))*2*a) #Depth of the land\n", "\n", "#Result\n", "print'(1) Attenuation = %.1f Np/m'%a\n", "print' Phase = %.1f Rad/m'%b\n", "print' Propagation constant = %.1f'%y.real\n", "print' + %.1f j rad/m'%y.imag\n", "print'(2) Depth of land = %.2f m'%z" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(1) Attenuation = 0.7 Np/m\n", " Phase = 0.7 Rad/m\n", " Propagation constant = 0.7\n", " + 0.7 j rad/m\n", "(2) Depth of land = 0.49 m\n" ] } ], "prompt_number": 34 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.6, page 38" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "W=100*10**-12 #power in watt\n", "no=120*math.pi\n", "\n", "#Calculation\n", "Em=math.sqrt(2*no*W) #effective value of E\n", "Ee=Em/math.sqrt(2) #effective value of E\n", "Hm=math.sqrt((2*10**-10)/(no)) #effective value of H\n", "He=Hm/math.sqrt(2) #effective value of H\n", "\n", "#Result\n", "print'Em = %.1f uV/m'%(Em*10**6)\n", "print'Ee = %.1f uV/m'%(Ee*10**6)\n", "print'Hm = %.3f uA/m'%(Hm*10**6)\n", "print'He = %.2f uA/m'%(He*10**6)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Em = 274.6 uV/m\n", "Ee = 194.2 uV/m\n", "Hm = 0.728 uA/m\n", "He = 0.52 uA/m\n" ] } ], "prompt_number": 42 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.7, page 39" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "f=7.5 #frequency in GHz\n", "d=40 #link distance in Km\n", "Pt=30 #transmitter power in dBm\n", "La=15 #additional loss\n", "Pth=-78 #RX threshold\n", "\n", "#Calculation\n", "FSL=92.4+(20*math.log10(f*d)) #FSL\n", "RSL=Pt-(0.4*FSL)-La #RSL\n", "FM=RSL-Pth #fade margin\n", "\n", "#Result\n", "print'(1) Received signal level (RSL) = %.1f dBm'%RSL\n", "print'(2) Fade margin = %.1f dB'%FM\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(1) Received signal level (RSL) = -41.8 dBm\n", "(2) Fade margin = 36.2 dB\n" ] } ], "prompt_number": 43 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.8, page 45" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "Pt=10 #transmitter power in watt\n", "Gt=5 #antenna power in dBm\n", "Lt=2 #feeder loss in dB\n", "d=8000 #distance in meter\n", "no=120*math.pi\n", "\n", "#Calculation\n", "EIRP=Pt+Gt-Lt \n", "x=EIRP*10**-1 \n", "EIRP2=10**x #Equivalent isotropic radiated power\n", "Ed=math.sqrt(30*EIRP2)/d #Electric Field Intensity\n", "W=(Ed**2)/(2*no) #power in watt\n", "\n", "#Result\n", "print'EIRP = %.1f W'%EIRP2\n", "print'|Ed| = %.2f mV/m'%(Ed*10**3)\n", "print'W = %.1f nW/m^2'%(W*10**9)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "EIRP = 20.0 W\n", "|Ed| = 3.06 mV/m\n", "W = 12.4 nW/m^2\n" ] } ], "prompt_number": 44 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.9, page 47" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "FSL=128 #FSL in dB\n", "Lb=135 #Sum of FSL and medium loss Lm\n", "Lc=5\n", "Gt=30 #transmitter gain in dB\n", "Gr=30 #reciever gain in dB\n", "Pr=-60 #received signal level\n", "\n", "#Calculation\n", "Lm=Lb-FSL #medium loss in dB\n", "Lm1=10**(Lm*10**-1) #medium loss\n", "Pt=Lc+Lb-Gt-Gr+Pr #power in dBm\n", "Pt1=10**(Pt*10**-1) #power in watt \n", "\n", "#Result\n", "print'Medium Loss = %d'%Lm1\n", "print'Pt = %.1f mW'%(Pt1)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Medium Loss = 5\n", "Pt = 100.0 mW\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.10, page 50" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "ri1=1.00025 #refractive index\n", "ri2=1.00023 #refractive index\n", "h1=1 #height in Km\n", "h2=1.5 #height in Km\n", "n=1.00026 #variation\n", "\n", "\n", "#Calculation\n", "deln=ri1-ri2\n", "delh=h2-h1\n", "d=deln/delh\n", "R=n/d #radius of curvature\n", "\n", "\n", "#Result\n", "print'Radiowave curvature radius, R = %.d Km'%R" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radiowave curvature radius, R = 25006 Km\n" ] } ], "prompt_number": 47 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.11, page 51" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Initialisation\n", "R=25000 #path curvature radius in Km\n", "Re=6370 #Earth radius in Km\n", "\n", "\n", "#Calculation\n", "K=R*(R-Re)**-1 #K factor\n", "Re1=K*Re #equivalent radii of the Earth\n", "R1=(1*Re1**-1)-(1*Re**-1)+(1*R**-1)\n", "d=1*R1**-1 #equivalent radii of the path\n", "\n", "\n", "#Result\n", "print'K = %.3f'%K\n", "print'Re1 = %d'%Re1\n", "print'R1 = %d'%d\n", "print'Therefore, R1 ~ infinity'" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "K = 1.342\n", "Re1 = 8548\n", "R1 = 147573952589676412928\n", "Therefore, R1 ~ infinity\n" ] } ], "prompt_number": 48 } ], "metadata": {} } ] }