{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 12 Transmission Lines" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.1 Page no 573" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "L=73.75*10**-9 #inductance, H\n", "C=29.5*10**-12 #capacitance\n", "x=5280\n", "\n", "#calculation\n", "import math\n", "Z=math.sqrt(L/C)\n", "z1=math.sqrt((x*L)/(x*C))\n", "\n", "#result\n", "print\"characterstics impedence for 1-ft =\",Z,\"ohm\"\n", "print\"characterstics impedence for 1-mi = \",z1,\"ohm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "characterstics impedence for 1-ft = 50.0 ohm\n", "characterstics impedence for 1-mi = 50.0 ohm\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.2 Page no 574" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "a=2 #parallel wire line\n", "b=2.35 #coaxial line\n", "D=0.285\n", "d=0.08\n", "e=1.0 #dielectric constant of insulating material relative to air\n", "\n", "#calculation\n", "import math\n", "z=(276/e)*math.log10(2*2)\n", "z1=(138/e)*math.log10(b)\n", "z2=(138/math.sqrt(2.3)*math.log10(D/d))\n", "\n", "#result\n", "print\"(a) characterstics impedence for a parallel wire = \",round(z,0),\"ohm\"\n", "print\"(b) characterstics impedence for a air dielectric coaxial line= \",round(z1,1),\"ohm\"\n", "print\"(c) characterstics impedence = \",round(z2,0),\"ohm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) characterstics impedence for a parallel wire = 166.0 ohm\n", "(b) characterstics impedence for a air dielectric coaxial line= 51.2 ohm\n", "(c) characterstics impedence = 50.0 ohm\n" ] } ], "prompt_number": 7 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.3 Page no 579" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "L=73.75*10**-9 #inductance, H\n", "C=29.5*10**-12 #capacitance\n", "d=1 #distance\n", "\n", "#calculation\n", "import math\n", "t=math.sqrt(L*C)\n", "Vp=d/t\n", "\n", "#result\n", "print\"the delay introduced is t =\",round(t,10),\"s\"\n", "print\"The velocity of propagation is \",round(Vp*10**-8,3),\"*10**8 ft/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "the delay introduced is t = 1.5e-09 s\n", "The velocity of propagation is 6.78 *10**8 ft/s\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.4 Page no 580" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "v=2.07*10**8 #velocity\n", "c=3.0*10**8 #velocity of light\n", "Er=2.3 #relative dielectric constant\n", "\n", "#calculation\n", "import math\n", "vf=(v/c) #velocity factor\n", "vf1=1/math.sqrt(Er)\n", "\n", "#result\n", "print\"The velocity = \",vf,\"m/s\"\n", "print\"vf = \",round(vf1,3)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The velocity = 0.69 m/s\n", "vf = 0.659\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.5 Page no 581" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "c=3*10**8 #speed of light\n", "f=100.0*10**6 #frequency of signal\n", "x=2.07*10**8 #velocity of wave propagation\n", "\n", "#Calcultion\n", "w=c/f #wavelength in free-space\n", "w1=x/f #wavelength while traveling through an RG-8A/U coaxial cable\n", "\n", "#Result\n", "print\"In free space, lambda =\",w,\"m\"\n", "print\"While traveling through RG-8A/U cable, lamda= \",w1,\"m\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "In free space, lambda = 3.0 m\n", "While traveling through RG-8A/U cable, lamda= 2.07 m\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.7 Page no 592" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "Zl=300.0 #load impedance\n", "Zo=50.0 #characteristic impedance\n", "v=2.07*10**8 #velocity in RG-8A/U cable\n", "f=27.0*10**6 #operating frequency of citizen's band transmitter\n", "Po=4 #output power of transmitter\n", "l=10 #length of RG-8A/U cable\n", "Rl=300 #input resistance of antenna\n", "\n", "#calculation\n", "T=((Zl-Zo)/(Zl+Zo)) #reflection coefficient\n", "h=v/f #length of cable in wavelength\n", "le=l/h #electrical length\n", "x=Rl/Zo #VSWR\n", "y=((1+T)/(1-T)) #VSWR\n", "rp=(T)**2*Po #reflected power\n", "Pl=Po-rp #load power\n", "#part(a): The reflection coefficient\n", "\n", "#result\n", "print\"(a) reflection cofficient = \",round(T,2)\n", "print\"(b) electrical length =\",round(le,2),\"lambda\"\n", "print\"(c) VSWR = \",y\n", "print\"(d) the reflected voltage = \",round(Pl,2),\"W\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) reflection cofficient = 0.71\n", "(b) electrical length = 1.3 lambda\n", "(c) VSWR = 6.0\n", "(d) the reflected voltage = 1.96 W\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.8 Page no 597" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "Zo=100.0 #characteristic impedance\n", "j=1j\n", "Zl = 200-j*150 #load impedance\n", "l=4.3 #length of transmission line\n", "\n", "#calculation\n", "x=200/Zo\n", "y=150/Zo\n", "a=0.4*Zo\n", "b=0.57*Zo\n", "\n", "#result\n", "print\"Zin = \",a,\"Ohm\",\"+j*\",b,\"Ohm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Zin = 40.0 Ohm +j* 57.0 Ohm\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.9 Page no 599" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "import cmath\n", "j=1j\n", "RL=120 #load resistance from smith chart\n", "ZL=complex(75,50) #load impedance\n", "Z0=50.0 #characteristic impedance\n", "\n", "#calculation\n", "import math\n", "z1=ZL/Z0\n", "z=2.4 #normalized z at a point that is purely resistive\n", "ar=z*Z0 #actual resistance\n", "x=math.sqrt(Z0*RL)\n", "\n", "#Result\n", "print\"zl= \",z1\n", "#VSWR,zin,R can be found out from smith chart manually\n", "print\"characteristic impedance is =\",round(x,2),\"ohm\" \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "zl= (1.5+1j)\n", "characteristic impedance is = 77.46 ohm\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 12.10 Page no 601" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "import cmath\n", "Z0=75.0 #characteristic impedance\n", "j=1j\n", "ZL=complex(50,-100) #load impedance\n", "\n", "#Calculation\n", "zL=ZL/Z0\n", "#Result\n", "print\"zL =\",zL\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "zL = (0.666666666667-1.33333333333j)\n" ] } ], "prompt_number": 7 } ], "metadata": {} } ] }