{ "metadata": { "name": "", "signature": "sha256:700ab6262dd3fd322aa3ece04f53175fb8f709a487cc0649654e8878a7afd58c" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "chapter09:Solid State Microwave devices" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.1, Page number 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Frequncy of IMPATT diode\n", "#Variable declaration\n", "L = 2*10**-6 #drift length(m)\n", "Vd = 10**7*10**-2 #dfrift velocit(m/s)\n", "\n", "#Calculations\n", "f = Vd/(2*L)\n", "\n", "#Results\n", "print \"Frequncy of IMPATT diode is\",round((f/1E+9),2),\"GHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Frequncy of IMPATT diode is 25.0 GHz\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.2, Page number 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate threshold electric field\n", "#Variable declaration\n", "f = 10*10**9 #operating frequency(Hz)\n", "L = 75*10**-6 #device length(m)\n", "V = 25. #voltage pulse amplified(V)\n", "\n", "#Calculations\n", "Eth = V/(L)\n", "\n", "#Result\n", "print \"The threshold electric field is\",round((Eth/1E+5),2),\"KV/cm\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The threshold electric field is 3.33 KV/cm\n" ] } ], "prompt_number": 2 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.3, Page number 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Power gain,Power gain as USB converter\n", "#chapter-9 page 411 example 9.3\n", "import math\n", "fs=2.*10.**9.;#Signal Frequency in Hz\n", "fp=12.*10.**9.#Pump Frequency in Hz\n", "Ri=16.;#O/P resistance of signal generator in ohms\n", "Rs=1000.;#On types resistance of signal generator in ohms\n", "\n", "#CALCULATION\n", "P=10*math.log10((fp-fs)/fs);#Power gain in dB\n", "Pusb=10*math.log10((fp+fs)/fs);#Power gain as USB converter in dB\n", "\n", "#OUTPUT\n", "print '%s %.2f %s %s %.2f %s' %('Power gain is P=',P,'dB','\\nPower gain as USB converter is Pusb=',Pusb,'dB')\n", "\n", "#Note: Answer given in textbook is wrong Check it once..\n", "#Correct answers are Power gain is P=6.99 dB \n", "#Power gain as USB converter is Pusb=8.45 dB \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power gain is P= 6.99 dB \n", "Power gain as USB converter is Pusb= 8.45 dB\n" ] } ], "prompt_number": 3 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.4, Page number 411" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Critical voltage ,Breakdown voltage,Breakdown electric field \n", "#Variable declaration\n", "Es = 12.5 #relative dielectric constant\n", "N = 3.2*10**22 #donor concentration(/m**3)\n", "L = 8*10**-6 #length(m)\n", "Eo = 8.854*10**-12 #dielectric constant\n", "q = 1.6*10**-19\n", "\n", "#Calculations\n", "#Part a\n", "Vc = (q*N*L**2)/(2*Eo*Es)\n", "\n", "#Part b\n", "Vbd = 2*Vc\n", "\n", "#Part c\n", "Ebd = Vbd/L\n", "\n", "#Results\n", "print \"Critical voltage =\",round((Vc/1E+3),2),\"kV\"\n", "print \"Breakdown voltage =\",round((Vbd/1E+3),2),\"kV\"\n", "print \"Breakdown electric field =\",round((Ebd/1E+8),2),\"*10**8 V/cm\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Critical voltage = 1.48 kV\n", "Breakdown voltage = 2.96 kV\n", "Breakdown electric field = 3.7 *10**8 V/cm\n" ] } ], "prompt_number": 4 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.5, Page number 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate avalanche zone velocity\n", "#Variable declaration\n", "Na = 2.5*10**16 #doping concentration(/cm**3)\n", "J = 33*10**3 #current density(A/cm**2)\n", "q = 1.6*10**-19\n", "\n", "#Calculations\n", "Vz = J/(q*Na)\n", "\n", "#Results\n", "print \"The avalanche zone velocity is\",round((Vz/1E+6),2),\"*10**6 cm/s\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The avalanche zone velocity is 8.25 *10**6 cm/s\n" ] } ], "prompt_number": 5 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.6, Page number 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate power gain\n", "#Variable declaration\n", "Rd = -25 #negative resistance(Ohms)\n", "Rl = 50 #load resistance(Ohms)\n", "\n", "#Calculations\n", "G = ((Rd-Rl)/(Rd+Rl))**2\n", "\n", "#Results\n", "print \"Power gain =\",G" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Power gain = 9\n" ] } ], "prompt_number": 6 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.7, Page number 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate minimum voltage required\n", "#chapter-9 page 412 example 9.7\n", "#For a Gunn Diode\n", "L=5.*10.**(-4.);#Drift Length in cm\n", "Vg=3300.;#Voltage gradient in V/cm [Vg>3.3 kV/cm]\n", " \n", "#CALCULATION\n", "Vmin=Vg*L;#Minimum Voltage needed to initiate Gunn effect in volts\n", "\n", "#OUTPUT\n", "print '%s %.2f %s' %('\\nMinimum Voltage needed to initiate Gunn effect is Vmin=',Vmin,'volts');\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Minimum Voltage needed to initiate Gunn effect is Vmin= 1.65 volts\n" ] } ], "prompt_number": 8 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.8, Page number 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Natural(Rational) Frequency,Critical Voltage of the diode\n", "#chapter-9 page 412 example 9.8\n", "#For a Gunn Diode\n", "L=20.*10.**(-4.);#Active Length in cm\n", "Vd=2.*10.**7.;#Drift Velocity of Electrons in cm/sec\n", "Ec=3.3*10.**3.;#Criticl Field for GaAs in V/cm\n", "\n", "#CALCULATION\n", "fn=(Vd/L)/10.**9.;#Natural(Rational) Frequency in GHz\n", "Vc=L*Ec;#Critical Voltage of the diode in volts\n", "\n", "#OUTPUT\n", "print '%s %.f %s %s %.1f %s ' %('\\nNatural(Rational) Frequency is fn=',fn,'GHz','\\nCritical Voltage of the diode is Vc=',Vc,'volts');\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "\n", "Natural(Rational) Frequency is fn= 10 GHz \n", "Critical Voltage of the diode is Vc= 6.6 volts \n" ] } ], "prompt_number": 9 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.9, Page number 412" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate the resonant frequency,Efficiency\n", "from math import pi,sqrt\n", "\n", "#Variable declaration\n", "Cj = 0.5*10**-12 #capacitance of IMPATT diode(F)\n", "Lp = 0.5*10**-9 #Inductance of IMPATT diode(H)\n", "Vbd = 100 #breakdown voltage(V)\n", "Ib = 100*10**-3 #dc bias current(A)\n", "Ip = 0.8 #peak current(A)\n", "Rl = 2 #load resistance(Ohms)\n", "\n", "#Calculations\n", "f = 1/(2*pi*sqrt(Lp*Cj))\n", "Pl = ((Ip**2)*Rl)/2\n", "Pdc = Vbd*Ib\n", "N = (Pl/Pdc)*100\n", "\n", "#Results\n", "print \"The resonant frequency is\",round((f/1E+9)),\"GHz\"\n", "print \"Efficiency is\",round(N,2),\"%\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The resonant frequency is 10.0 GHz\n", "Efficiency is 6.4 %\n" ] } ], "prompt_number": 10 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.10, Page number 413" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Drift time of the carrier,Operating frequency of diode\n", "\n", "#Variable declaration\n", "Vd = 10**5 #carrier dirft velocity(cm/s)\n", "L = 2*10**-6 #drift length(m)\n", "\n", "#Calculations\n", "#Part a\n", "tou = L/Vd\n", "\n", "#Part b\n", "f = 1/(2*tou)\n", "\n", "#Results\n", "print \"Drift time of the carrier is\",round((tou/1E-11),2),\"*10**-11 sec\"\n", "print \"Operating frequency of diode is\",(f/1E+9),\"GHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Drift time of the carrier is 2.0 *10**-11 sec\n", "Operating frequency of diode is 25.0 GHz\n" ] } ], "prompt_number": 11 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.11, Page number 413" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Breakdown voltage,Breakdown electric field\n", "\n", "#Variable declaration\n", "Er = 11.8 #relative dielectric constant\n", "N = 3*10**21 #donor concentration(m^-3)\n", "L = 6.2*10**-6 #Si length(m)\n", "q = 1.6*10**-19 #charge of an electron(C)\n", "Eo = 8.854*10**-12 #dielctric constant\n", "\n", "#Calculations\n", "#Part a\n", "Vbd = (q*N*L**2)/(Eo*Er)\n", "\n", "#Part b\n", "Ebd = Vbd/L\n", "\n", "#Results\n", "print \"Breakdown voltage =\",round(Vbd,1),\"V\"\n", "print \"Breakdown electric field =\",round((Ebd/1E+7),2),\"*10**7 V/m\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Breakdown voltage = 176.6 V\n", "Breakdown electric field = 2.85 *10**7 V/m\n" ] } ], "prompt_number": 12 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.12, Page number 413" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Maximum power gain,Noise figure,Bandwidth\n", "\n", "import math\n", "\n", "#Variable declaration\n", "rQ = 8. #figure of merit\n", "fo_fs = 8. #ratio of o/p to i/p frequency\n", "Td = 300. #diode temperatur(K)\n", "To = 300. #ambient temperature(K)\n", "r = 0.2\n", "\n", "#Calculations\n", "#Part a\n", "X = rQ**2/fo_fs\n", "G = (X/((1+math.sqrt(1+X))**2))*fo_fs\n", "g = 10*math.log10(G)\n", "\n", "#Part b\n", "F = 1+((2*Td)/To)*((1/rQ)+(1/rQ**2))\n", "f = 10*math.log10(F)\n", "\n", "#Part c\n", "BW = 2*r*math.sqrt(fo_fs)\n", "\n", "#Results\n", "print \"Maximum power gain =\",round(g,2),\"dB\"\n", "print \"Noise figure =\",round(f,2),\"dB\"\n", "print \"Bandwidth =\",round(BW,2)" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Maximum power gain = 6.02 dB\n", "Noise figure = 1.08 dB\n", "Bandwidth = 1.13\n" ] } ], "prompt_number": 13 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 9.13, Page number 414" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate Equivalent noise resistance,Gain,Noise figure,Bandwidth\n", "#Variable declaration\n", "import math\n", "fs = 2*10**9 #signal frequency(Hz)\n", "fp = 12*10**9 #amplifier frquency(Hz)\n", "fi = 10*10**9 #input frequency(Hz)\n", "fd = 5*10**9 #diode frequency(Hz)\n", "Ri = 1*10**3 #input resistance(Ohms)\n", "Rg = 1*10**3 #gate resistance(Ohms)\n", "RTs = 1*10**3 #resistance(Ohms)\n", "RTi = 1*10**3 #resistance(Ohms)\n", "r = 0.35 #resistane(Ohms)\n", "rQ = 10. #figure of merit\n", "rd = 300 #diode temperature(K)\n", "C = 0.01*10**-12 #capacitance(F)\n", "Td = 300\n", "To = 300\n", "\n", "#Calculations\n", "#Part a\n", "ws = 2*math.pi*fs\n", "wi = 2*math.pi*fi\n", "R = (r**2)/(ws*wi*C**2*RTi)\n", "a = R/RTs\n", "\n", "#Part b\n", "G = (4*fi*Rg*Ri*a)/(fs*RTs*RTi*(1-a)**2)\n", "g = 10*math.log10(G)\n", "\n", "#Part c\n", "F = 1+((2*Td)/To)*((1/rQ)+(1/rQ**2))\n", "f = 10*math.log10(F)\n", "\n", "#Part d\n", "BW = (r/2)*math.sqrt(fd/(fs*G))\n", "\n", "#Results\n", "print \"Equivalent noise resistance =\",round(a,2),\"Ohms\"\n", "print \"Gain =\",round(g,1),\"dB\"\n", "print \"Noise figure =\",round(f,2),\"dB\"\n", "print \"Bandwidth =\",round(BW,3),\"(Calculation error in the textbook)\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Equivalent noise resistance = 1.55 Ohms\n", "Gain = 20.1 dB\n", "Noise figure = 0.86 dB\n", "Bandwidth = 0.027 (Calculation error in the textbook)\n" ] } ], "prompt_number": 14 } ], "metadata": {} } ] }