{ "metadata": { "name": "" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 14 Antennas" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.1 Page no 669" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "c=3*10**8 #m/s , speed of light \n", "f=150*10**6 #frequency\n", "\n", "#calculation\n", "h=c/f\n", "x=1/2.0 #antennas dimension(D)\n", "D=0.5*2\n", "Rff=5*D\n", "h=c/f \n", "D = h/2\n", "\n", "#result\n", "print\" distance =\",Rff,\"m\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " distance = 5.0 m\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.2 Page no 669" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "c=3*10**8 #velocity of light\n", "f=12.0*10**9 #frequency\n", "D=4.5 #diameter of parabolic reflector\n", "\n", "#calculation\n", "h=c/f #wavelength\n", "x=D/h\n", "R=(2*D**2)/h\n", "\n", "#result\n", "print\"distance from parabolic reflector= \",R,\"m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "distance from parabolic reflector= 1620.0 m\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.3 Page no 671" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#given\n", "Pt=10 #transmitted power\n", "#dipoles have gain 2.15dB \n", "Gr=1.64\n", "c=3*10**8 #velocity of light\n", "f=144.0*10**6 #frequency\n", "d=50*10**3 #distance between antennas\n", "Gt=1.64 #recieving antenna gain(ratio) compared to isotropic radiator\n", "\n", "#calculation\n", "import math\n", "Pr=Pt*Gt*Gr*(c/f)**2/((16*(math.pi)**2)*(d**2)) #power recieved\n", "\n", "#result\n", "print\"Power received = \",round(Pr,12),\"w\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power received = 2.96e-10 w\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 14.4 Page no 674" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Given\n", "c=3*10**8 #velocity of light\n", "f=100*10**6 #frequency\n", "\n", "#Calculation\n", "h=c/f #wavelength\n", "x=h/2.0 #dipole i.e h/2\n", "l=0.95*x #applying 95% correction,the actual optimum physical length\n", "L=486/100.0 #alternative method to find length\n", "\n", "#Result\n", "print\"length of antenna = \",l,\"m\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "length of antenna = 1.425 m\n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }