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diff --git a/Antennas_and_Wave_Propagation/chapter8.ipynb b/Antennas_and_Wave_Propagation/chapter8.ipynb new file mode 100644 index 00000000..3c5e8930 --- /dev/null +++ b/Antennas_and_Wave_Propagation/chapter8.ipynb @@ -0,0 +1,192 @@ +{ + "metadata": { + "name": "" + }, + "nbformat": 3, + "nbformat_minor": 0, + "worksheets": [ + { + "cells": [ + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "<h1>Chapter 8: Helical Antennas<h1>" + ] + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "<h3>Example 8-5.1, Page number: 309<h3>" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from math import sqrt\n", + "\n", + "#Variable declaration\n", + "w = 5 #Width of flattened tubing at termination (mm)\n", + "Er = 2.7 #Relative permittivity of the sheet\n", + "Z0 = 50 #Characteristic impdence of the sheet\n", + "\n", + "#Calculation\n", + "h = w/((377/(sqrt(Er)*Z0))-2)\n", + "\n", + "#Result\n", + "print \"The required thickness of the polystyrene sheet is\", round(h,1),\"mm\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The required thickness of the polystyrene sheet is 1.9 mm\n" + ] + } + ], + "prompt_number": 1 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "<h3>Example 8-5.2, Page number:315<h3>" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from math import sqrt, log10\n", + "\n", + "#Variable declaration\n", + "n = 16.0 #Number of turns (unitless)\n", + "C = 1 #Circumference (lambda)\n", + "S = 0.25 #Turn Spacing (lambda)\n", + "\n", + "#Calculation\n", + "hpbw = 52/(C*sqrt(n*S)) #Half power beamwidth (degrees)\n", + "ax_rat = (2*n + 1)/(2*n) #Axial ratio (unitless)\n", + "gain = 12*(C**2)*n*S #Gain of antenna (unitless)\n", + "gain_db = 10*log10(gain) #Gain of antenna (in dBi)\n", + "\n", + "print \"The half power beam width is\", hpbw, \"degrees\"\n", + "print \"The axial ratio is\", round(ax_rat,2)\n", + "print \"The gain is\", gain,\"or\",round(gain_db,1),\"dBi\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The half power beam width is 26.0 degrees\n", + "The axial ratio is 1.03\n", + "The gain is 48.0 or 16.8 dBi\n" + ] + } + ], + "prompt_number": 2 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "<h3>Example 8-5.3, Page number:316<h3>" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from math import pi, sqrt, log10\n", + "\n", + "#Variable declaration\n", + "n = 10.0 #Number of turns (unitless)\n", + "S = 0.236 #Spacing between turns (lambda)\n", + "n_a = 4.0 #Number of helical antennas in the array (unitless)\n", + "\n", + "#Calculation\n", + "D = 12*n*S #Directivity of a single antenna(unitless)\n", + "Ae = D/(4*pi) #Effective aperture (lambda^2)\n", + "\n", + "A = sqrt(Ae) #Area of square/spacing between helixes (lambda)\n", + "Ae_total = Ae*n_a #Total effective aperture (lambda^2)\n", + "D_array = (4*pi*Ae_total) #Directivity of the array (unitless)\n", + "D_array_db = 10*log10(D_array) #Direcitivity of the array (dBi)\n", + "\n", + "#Result\n", + "print \"The best spacing between the helixes is\", round(A,1), \"lambda\"\n", + "print \"The directivity of the array is\", round(D_array),\"or\",round(D_array_db,1),\"dBi\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The best spacing between the helixes is 1.5 lambda\n", + "The directivity of the array is 113.0 or 20.5 dBi\n" + ] + } + ], + "prompt_number": 4 + }, + { + "cell_type": "markdown", + "metadata": {}, + "source": [ + "<h3>Example 8-16.1, Page number:347<h3>" + ] + }, + { + "cell_type": "code", + "collapsed": false, + "input": [ + "from math import pi\n", + "\n", + "#Variable declaration\n", + "gain = 24.0 #Gain (dB)\n", + "alpha = 12.7 #Pitch angle (degrees)\n", + "c_lambda = 1.05 #Circumference (lambda)\n", + "s_lambda = 0.236 #Spacing between turns (lambda)\n", + "\n", + "#Calculation\n", + "D = 10**(gain/10) #Directivity (unitless)\n", + "L = D/(12*(c_lambda**2)) #Helix length (lambda)\n", + "n = L/s_lambda #Number of turns (unitless)\n", + "D = D/4 #Directivity for four 20-turn helixes(unitless)\n", + "Ae = D/(4*pi) #Effective aperture of each helix (lambda^2)\n", + "\n", + "#Result\n", + "print \"The Axial length is\", round(L),\"lambda\"\n", + "print \"The number of turns for the axial length is\",round(n)\n", + "print \"The effective aperture for 20 turns is\",round(Ae),\"lambda^2\"" + ], + "language": "python", + "metadata": {}, + "outputs": [ + { + "output_type": "stream", + "stream": "stdout", + "text": [ + "The Axial length is 19.0 lambda\n", + "The number of turns for the axial length is 80.0\n", + "The effective aperture for 20 turns is 5.0 lambda^2\n" + ] + } + ], + "prompt_number": 4 + } + ], + "metadata": {} + } + ] +}
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