{ "metadata": { "name": "", "signature": "sha256:cd13dfdb6dd7420874a1c992512f922297a6fa769a755d9c2c04bb32f02bdf3a" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 7: Radio Transmitters and Receivers " ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.1, page no. 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration\n", "fs1 = 1.00*pow(10,6) # Sampling Frequency (Hz)\n", "fs2 = 25.00*pow(10,6) # Sampling Frequency (Hz)\n", "fi = 455.00*pow(10,3) # Intermediate Frequency (Hz)\n", "Q = 100.00 # Loaded Q of the antenna coupling circuit \n", "\n", "# Calculation\n", "import math # Math Library\n", "fsi1 = fs1+2*fi # Image Frequency (Hz)\n", "rho1 = fsi1/fs1-fs1/fsi1 # Constant 1\n", "alpha1 = math.sqrt(1+pow(Q*rho1,2)) # Rejection Ratio 1\n", "fsi2 = fs2+2*fi # Image Frequency (Hz) \n", "rho2 = fsi2/fs2-fs2/fsi2 # Constant 2\n", "alpha2 = math.sqrt(1+pow(Q*rho2,2)) # Rejection Ratio 2\n", "\n", "# Result\n", "print \"(a) Image Frequency, fsi =\",fsi1/pow(10,3),\"kHz\"\n", "print \" rho =\",round(rho1,3)\n", "print \" Image Rejection, Alpha =\",round(alpha1,1)\n", "print \"(b) Image Frequency, fsi =\",fsi2/pow(10,6),\"MHz\"\n", "print \" rho =\",round(rho2,4)\n", "print \" Image Rejection, Alpha =\",round(alpha2,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) Image Frequency, fsi = 1910.0 kHz\n", " rho = 1.386\n", " Image Rejection, Alpha = 138.6\n", "(b) Image Frequency, fsi = 25.91 MHz\n", " rho = 0.0715\n", " Image Rejection, Alpha = 7.22\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.2, page no. 153" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration\n", "alpha1 = 138.6 # Image Rejection From Example 7.1\n", "alpha2 = 7.22 # Image Rejection From Example 7.1\n", "rho = 0.0715 # Constant From Example 7.1\n", "Q = 100.00 # Loaded Q From Example 7.1\n", "fsi_dash = 1.91*pow(10,6) # Image Frequency (Hz)\n", "fs_dash = 1.00*pow(10,6) # Sampling Frequency 1 (Hz)\n", "fs = 25.00*pow(10,6) # Sampling Frequency 2 (Hz)\n", "\n", "\n", "# Calculation\n", "import math # Math Library\n", "Q_dash = math.sqrt(pow(alpha1/alpha2,2)-1)/rho # Loaded Q of the RF amplifier\n", "fi_dash = (fsi_dash/fs_dash*fs-fs)/2 # Intermediate Frequency (Hz) \n", "\n", "# Result\n", "print \"(a) The Q of the circuit is\",round(math.sqrt(Q*Q_dash)),\", which is the geometric mean of\",round(Q),\"and\",round(Q_dash)\n", "print \"(b) Intermediate Frequency, fi_dash =\",round(fi_dash/pow(10,6),1),\"MHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "(a) The Q of the circuit is 164.0 , which is the geometric mean of 100.0 and 268.0\n", "(b) Intermediate Frequency, fi_dash = 11.4 MHz\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 7.3, page no. 164" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "# Variable Declaration\n", "R1 = 110.00*pow(10,3) # RESISTANCE 1 (Ohms)\n", "R2 = 220.00*pow(10,3) # RESISTANCE 2 (Ohms)\n", "R3 = 470.00*pow(10,3) # RESISTANCE 3 (Ohms)\n", "R4 = 1.00*pow(10,6) # RESISTANCE 4 (Ohms)\n", "\n", "# Calculation\n", "import math # Math Library\n", "Rc = R1+R2 # Resistance (Ohm)\n", "Zm = R2*R3*R4/(R2*R3+R3*R4+R2*R4)+R1 # Impedance (Ohm)\n", "m_max = Zm/Rc # Maximum Modulation Index\n", "\n", "# Result\n", "print \"Maximum Modulation Index, m_max =\",round(m_max*pow(10,2)),\"%\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum Modulation Index, m_max = 73.0 %\n" ] } ], "prompt_number": 4 } ], "metadata": {} } ] }