{ "metadata": { "name": "", "signature": "sha256:e0413e9c9e3050091f310d4afb4ca2e525621132a18cab203347bc4619b6cd5d" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "chapter10:Microwave Communication Systems" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.1, Page number 486" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate radio horizon and the maximum distance of propagation of the TV signal\n", "from math import sqrt\n", "\n", "#Variable declaration\n", "ht = 144 #transmitter antenna height(m)\n", "hr = 25 #receiving antenna height(M)\n", "\n", "#Calculations\n", "dt = 4*sqrt(ht)\n", "dr = 4*sqrt(hr)\n", "d = dt+dr\n", "\n", "#Results\n", "print \"Radio horizon is\",dt,\"km\"\n", "print \"The maximum distance of propagation of the TV signal is\",d,\"km\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radio horizon is 48.0 km\n", "The maximum distance of propagation of the TV signal is 68.0 km\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.2, Page number 486" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate horizon distance of the transmitter\n", "from fractions import Fraction\n", "\n", "#Variable declaration\n", "r = 6370*10**3 #radius of earth(km)\n", "du_dh = -0.05*10**-6 #refractive index of air near ground\n", "\n", "#Calculations\n", "k = 1/(1+(r*du_dh))\n", "\n", "#Result\n", "print \"The horizon distance of the transmitter can be modified by replaing r by r' is\",round(k,3),\"r\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The horizon distance of the transmitter can be modified by replaing r by r' is 1.467 r\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.3, Page number 487" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate carrier tansmitted power required\n", "import math \n", "#Variable declaration\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "f = 2*10**9 #frequency(Hz)\n", "r = 50*10**3 #repeater spacing(km)\n", "Pr = 20 #carrier power(dBm)\n", "Gt = 34 #antenna gain(dB)\n", "L = 10 #dB\n", "Gr = 34 #dB\n", "\n", "#Calculations\n", "lamda = c/f\n", "Pt = -Pr+(10*math.log10(4*math.pi*r**2))-Gt-(10*math.log10(lamda**2/(4*math.pi)))+L-Gr\n", "\n", "#Results\n", "print \"The carrier tansmitted power required is\",round(Pt,1),\"dBm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The carrier tansmitted power required is 54.4 dBm\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.4, Page number 487" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Received power\n", "import math\n", "\n", "#Variable declaration\n", "f = 6.*10**9 #uplink frequency(Hz)\n", "e = 5 #elevation angle(degrees)\n", "Pt = 1.*10**3 #transmitter power(W)\n", "Gt = 60. #gain of transmitter(dB)\n", "Gr = 0 #gain of receiver(dB)\n", "d = 36000*10**3 #distance between ground and satellite(m)\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "\n", "#Calculation\n", "Gt1 = 10**(Gt/10)\n", "Gr1 = 10.**(Gr/10)\n", "r = d/(math.sin(math.radians(e)))\n", "lamda = c/f\n", "Pr = (Pt*Gt1*Gr1*lamda**2)/(4*math.pi*r**2*4*math.pi)\n", "\n", "#Result\n", "print \"Received power =\",round((Pr/1E-14),1),\"*10^-14 W\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Received power = 9.3 *10^-14 W\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.5, Page number 487" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Antenna beam angle\n", "import math\n", "\n", "#Variable declaration\n", "r = 6371 #radius of the earth(km)\n", "\n", "#Calculation\n", "d = 35855+r #distance of satellite from center of the earth(km)\n", "b = (math.degrees(math.pi)*r)/d\n", "\n", "#Result\n", "print \"Antenna beam angle =\",round(b,2),\"degrees\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Antenna beam angle = 27.16 degrees\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.6, Page number 488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate round trip time between earth station and satellite,round trip time for vertical transmission\n", "import math\n", "\n", "#Variable declaration\n", "r = 6371 #radius of earth(km)\n", "h = 35855 #height(km) \n", "phi = 5 #elevation angle(degrees)\n", "c = 3*10**8 #velocity of propagation(m/s)\n", "B = 90 #angle for vertical transmission(degrees)\n", "\n", "#Calculations\n", "d = math.sqrt(((r+h)**2)-((r*math.cos(math.radians(phi)))**2))- (r*math.sin(math.radians(phi)))\n", "T = (2*d*10**3)/c\n", "dv = math.sqrt(((r+h)**2)-(r**2))\n", "Tv = (2*(dv-r)*10**3)/c\n", "\n", "#Results\n", "print \"The round trip time between earth station and satellite is\",round((T/1E-3)),\"msec\"\n", "print \"The round trip time for vertical transmission is\",round((Tv/1E-3)),\"msec\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The round trip time between earth station and satellite is 275.0 msec\n", "The round trip time for vertical transmission is 236.0 msec\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.7, Page number 488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate figure of merit for earth station\n", "import math\n", "\n", "#Variable declaration\n", "Tant = 25 #effective noise temperature for antenna(K)\n", "Tr = 75 #receiver oise temperature(K)\n", "G = 45 #power gain(dB)\n", "\n", "#Calculations\n", "T = Tant+Tr\n", "Tdb = 10*math.log10(T)\n", "M = G - Tdb\n", "\n", "#Results\n", "print \"The figure of merit for earth station is\",M,\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The figure of merit for earth station is 25.0 dB\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.8, Page number 488" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate carrier to noise ratio\n", "#Variable declaration\n", "EIRP = 55.5 #satellite ESM(dBW)\n", "M = 35 #freespace loss(dB)\n", "Lfs = 245.3 #GT of earth station(dB)\n", "\n", "#Calculation\n", "C_No = EIRP + M - Lfs + 228.6\n", "\n", "#Result\n", "print \"The carrier to noise ratio is\",round(C_No,2),\"dB\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The carrier to noise ratio is 73.8 dB\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.9, Page number 489" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate system noise temperature\n", "import math\n", "\n", "#Variable declaration\n", "D = 30 #diameter of dish(m)\n", "f = 4*10**9 #downlink frequency(Hz)\n", "M = 20 #G/T ratio of earth station\n", "c = 3.*10**8 #velocity of propagation(m/s)\n", "\n", "#Calculations\n", "Ae = (math.pi*D**2)/4\n", "lamda = c/f\n", "G = (4*math.pi*Ae)/lamda**2\n", "Gdb = 10*math.log10(G)\n", "Ts = Gdb - M\n", "\n", "#Result\n", "print \"The system noise temperature is\",round(Ts),\"dB\" " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The system noise temperature is 42.0 dB\n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.10, Page number 489" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#chapter-10 page 489 example 10.10\n", "#calculate Diameter of the circular mouth of a parabolic antenna, Half Power BeamWidth of the antenna\n", "#For a parabolic antenna\n", "import math\n", "Gp=1500.;#Power gain\n", "w=0.1;#wavelength in m\n", "\n", "#CALCULATION\n", "D=math.sqrt(Gp)*(w/(math.pi));#Diameter of the circular mouth of a parabolic antenna in m\n", "HPBW=58*(w/D);#Half Power BeamWidth of the antenna in deg\n", "\n", "#OUTPUT\n", "print '%s %.4f %s %s %.3f %s'%('\\nDiameter of the circular mouth of a parabolic antenna is D=',D,'m','\\nHalf Power BeamWidth of the antenna is HPBW=',HPBW,'deg');\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Diameter of the circular mouth of a parabolic antenna is D= 1.2328 m \n", "Half Power BeamWidth of the antenna is HPBW= 4.705 deg\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.11, Page number 490" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#chapter-10 page 490 example 10.11\n", "#calculate Overall gain that can be expected, Overall gain of the system\n", "import math\n", "D=1.;#Assume diameter of the parabolic reflectors in the original system in m\n", "w=1.;#Assume wavelength in m\n", "\n", "#CALCULATION\n", "D1=2.*D;#diameter of the parabolic reflectors in the modified system in m\n", "G=6.*(D/w)**2.;#gain in original system\n", "G1=6.*(D1/w)**2.;#gain in modified system\n", "GdB=10.*math.log10(G1/G);#Overall gain that can be expected in dB\n", "GdBo=2.*GdB;#Overall gain of the system(combining the two antennas one at the Tx and other at the Rx) in dB\n", "\n", "#OUTPUT\n", "print '%s %.f %s %s %.f %s' %('\\nOverall gain that can be expected is GdB=',GdB,'dB', '\\nOverall gain of the system(combining the two antennas one at the Tx and other at the Rx) is GdBo=',GdBo,'dB');\n", "\n", "#Note: Check the answer once ..it should be GdB=10log(4)=6 dB and GdBo=12dB\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Overall gain that can be expected is GdB= 6 dB \n", "Overall gain of the system(combining the two antennas one at the Tx and other at the Rx) is GdBo= 12 dB\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.12, Page number 490" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#chapter-10 page 490 example 10.12\n", "#calculate a)beamwidth between first nulls\n", "#calculate b)beamwidth between half power points\n", "\n", "\n", "D=3.##dimension of a paraboloid in m\n", "f=3.*10.**9.##frequency (S band) in Hz\n", "c=3.*10.**8.##Velocity of light in m/sec\n", "\n", "#CALCULATION\n", "w=c/f##wave length in m\n", "BWFN=140.*(w/D)##BeamWidth between First Nulls in deg\n", "BWHP=70.*(w/D)##BeamWidth between HalfPower points in deg\n", "G=6.*(D/w)**2.##Gain of the antenna \n", "\n", "#OUTPUT\n", "print '%s %.2f %s %s %.2f %s %s %.f' %('BeamWidth between First Nulls is BWFN=',BWFN,'deg','\\nBeamWidth between HalfPower points is BWHP=',BWHP,'deg','\\nGain of the Antenna is G=',G)#\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "BeamWidth between First Nulls is BWFN= 4.67 deg \n", "BeamWidth between HalfPower points is BWHP= 2.33 deg \n", "Gain of the Antenna is G= 5400\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 10.13, Page number 490" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate power gain of optimum horn antenna\n", "#Variable declaration\n", "A = 5\n", "\n", "#Calculation\n", "Gp = 4.5*A**2\n", "\n", "#Result\n", "print \"Power gain of optimum horn antenna =\",Gp\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power gain of optimum horn antenna = 112.5\n" ] } ], "prompt_number": 13 } ], "metadata": {} } ] }