{ "metadata": { "name": "", "signature": "sha256:036aa35bf5e5de2a2351f2b120a2084a8b3fc2b376331b57004e9eccc3893299" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 11: Antennas" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.1, page no. 292" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration\n", "f1 = 1.00*pow(10,6) # Operating Frequency (Hz)\n", "f2 = 10.00*pow(10,3) # Operating Frequency (Hz)\n", "c = 3.00*pow(10,8) # Speed of light in vacuum (m/s)\n", "\n", "# Calculation\n", "Lambda1 = c/f1 # Mechanical Length (m)\n", "Lambda2 = c/f2 # Mechanical Length (m)\n", "\n", "# Result\n", "print \"(a) Mechanical Length at 1 MHz, Lambda1 =\",round(Lambda1),\"m\"\n", "print \"(b) Mechanical Length at 10 kHz, Lambda2 =\",round(Lambda2),\"m\"\n", "print \" Increase in Length =\",round(Lambda2/Lambda1),\"times\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) Mechanical Length at 1 MHz, Lambda1 = 300.0 m\n", "(b) Mechanical Length at 10 kHz, Lambda2 = 30000.0 m\n", " Increase in Length = 100.0 times\n" ] } ], "prompt_number": 16 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.2, page no. 294" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "f = 1.00*pow(10,6) # Operating Frequency (Hz)\n", "Le = 30 # Hertzian Dipole Length (m)\n", "I = 5 # Current value (A)\n", "r = 1.00*pow(10,3) # Distance (m)\n", "Theeta = 90 # Angle (degrees)\n", "c = 3.00*pow(10,8) # Speed of light in vacuum (m/s)\n", "\n", "# Calculation\n", "import math\n", "Lambda = c/f # Wavelength (m)\n", "E = ((60*math.pi*Le*I)/Lambda*r)*math.sin(Theeta*math.pi/180) # Calculation of Field Strength (s/m)\n", "\n", "# Result\n", "print \"Field Strength at a distance of 1 km and at an angle of 90 degrees, E =\",round(E/(math.pi*pow(10,3))),\"*pi*10^(-3) us/m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Field Strength at a distance of 1 km and at an angle of 90 degrees, E = 30.0 *pi*10^(-3) us/m\n" ] } ], "prompt_number": 15 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.3, page no. 296" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "f = 500*pow(10,3) # Operating Frequency (Hz)\n", "vel = 3.00*pow(10,8) # Speed of light in vacuum (m/s)\n", "Vf = 0.95 # Velocity Factor\n", "\n", "# Calculation\n", "import math # Math Library\n", "Le = vel/f*Vf # Length of the antenna (m)\n", "\n", "# Result\n", "print \"The Length of the Antenna, Le =\",round(Le),\"m or\",round(Le*3.936),\"ft\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The Length of the Antenna, Le = 570.0 m or 2244.0 ft\n" ] } ], "prompt_number": 17 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.4, page no. 299" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "P1 = 1*pow(10,3) # Power of Half Wave Dipole antenna (w)\n", "A = 2.15 # Gain (dB)\n", "\n", "# Calculation\n", "import math # Math Library\n", "P2 = pow(10,A/10)*P1 # Power delivered (w)\n", "\n", "# Result\n", "print \"The power delivered to the isotropic antenna to match the field strength of directional antenna, P2 =\",round(P2,1),\"W\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The power delivered to the isotropic antenna to match the field strength of directional antenna, P2 = 1640.6 W\n" ] } ], "prompt_number": 18 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.5, page no. 300" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variable Declaration \n", "P = 1.00*pow(10,3) # Input Power (W)\n", "field_gain = 2 # Field Gain\n", "E = 0.5 # (*100) Efficiency (%)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Po = P*E # Power fed (W)\n", "erp = Po*pow(field_gain,2) # Effective Radiated Power (w)\n", "\n", "\n", "# Result\n", "print \" The Effective Radiated Power, erp =\",round(erp),\"W\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The Effective Radiated Power, erp = 2000.0 W\n" ] } ], "prompt_number": 19 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.6, page no. 300" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "P_in = 800 # Input Power (W)\n", "E_lost = 0.25 # (*100) Loss Percentage (%)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Pd = E_lost*P_in # Power Lost (W)\n", "P_rad = P_in-Pd # Radiated Power (W)\n", "\n", "# Result\n", "print \"Radiated Power, P_rad =\",round(P_rad),\"W\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Radiated Power, P_rad = 600.0 W\n" ] } ], "prompt_number": 20 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.7, page no. 301" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "\n", "# Variable Declaration \n", "R_rad = 100 # Radiation Resistance (Ohms)\n", "E = 0.75 # (*100) Efficiency (%)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Rd = R_rad/E-R_rad # Antenna Resistance (Ohms)\n", "\n", "# Result\n", "print \"Antenna Resistance, Rd =\",round(Rd,2),\"Ohms\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Antenna Resistance, Rd = 33.33 Ohms\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.8, page no. 309" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "Zs = 5 # Impedance of the transmission line (Ohms)\n", "Zr = 70 # Impedance of the antenna (Ohms)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Z = Zs*Zr # Characteristic Impedance (Ohms)\n", "\n", "# Result\n", "print \"The characteristic impedance of the matching section, Z =\",round(Z),\"Ohms\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The characteristic impedance of the matching section, Z = 350.0 Ohms\n" ] } ], "prompt_number": 21 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.9, page no. 316" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "D = 2 # Mouth diameter of reflector (m)\n", "f = 6.00*pow(10,9) # Operating Frequency (Hz)\n", "c = 3.00*pow(10,8) # Speed of light in vacuum (m/s)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Lambda = c/f # Wavelength (m)\n", "phi_o = 2*70*Lambda/D # Beam width between nulls of a paraboloid reflector (degrees)\n", "\n", "# Result\n", "print \"The beam width between nulls of a paraboloid reflector, phi_o =\",round(phi_o,1),\"degrees\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The beam width between nulls of a paraboloid reflector, phi_o = 3.5 degrees\n" ] } ], "prompt_number": 22 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 11.10, page no. 317" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration \n", "D = 200 # Mouth diameter of reflector (m)\n", "Lambda = 5 # Wavelength (m)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Ap = 6*pow(D/Lambda,2) # Gain of the antenna\n", "\n", "# Result\n", "print \" The gain of the antenna, Ap =\",round(Ap)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " The gain of the antenna, Ap = 9600.0\n" ] } ], "prompt_number": 13 } ], "metadata": {} } ] }