{ "metadata": { "name": "", "signature": "sha256:0febf6654b4226cea8bd31c369bda102743b50db8084bc6251d5320576f18189" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter6:MICROWAVE FIELD-EFFECT TRANSISTORS" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.1.1:pg-229" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculation of pinch-off voltage\n", "\n", "a=0.1*(10**-6) #channel height in m\n", "Nd=8*(10**23) #Electron Concetration in m-3\n", "er=11.80 #relative dielectric constant\n", "es=8.854*(10**-12)*er #permittivity of silicon in F/m\n", "q=1.6*(10**-19) #charge of electron in C\n", "Vp=(q*Nd*(a**2))/(2*es) #pinch-off voltage\n", "\n", "print\"Pinch-off volatge in(Volts)is=\",round(Vp,2),\"Volts\" #answer is wrong in book \n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pinch-off volatge in(Volts)is= 6.13 Volts\n" ] } ], "prompt_number": 1 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.1.2:pg-233" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#(a)Calculate the pinch-off Voltage in Volts\n", "a=0.2*(10**-4) #channel height in cm\n", "Nd=1*(10**17) #Electron density in /cm3\n", "er=11.80 #relative dielectric constant\n", "es=8.854*(10**-14)*er #permittivity of silicon in F/cm\n", "q=1.6*(10**-19) #charge of electron in C\n", "Vp=(q*Nd*(a**2))/(2*es) #pinch-off voltage\n", "print\"The pinch-off volatge in(Volts)is=\",round(Vp,2),\"V\"\n", "\n", "#(b)Calculate the pinch-off current\n", "un=800 #electron mobility in cm2/V.s\n", "L=8*(10**-4) #channel length in cm\n", "Z=50*(10**-4) #channel width in cm\n", "a=0.2*(10**-4) #channel height in cm\n", "Nd=1*(10**17) #Electron density in /cm3\n", "er=11.80 #relative dielectrin constant\n", "es=8.854*(10**-14)*er #permittivity of silicon in F/cm\n", "q=1.6*(10**-19) #charge of electron in C\n", "Ip=(un*(q**2)*(Nd**2)*Z*(a**3))/(L*es) #pinch-off voltage\n", "Ip=Ip*1000 # in mA\n", "print\"The pinch-off current in(mA)is=\",round (Ip,2),\"mA\"\n", "\n", "#(c)Calculate the built-in voltage\n", "Nd=1*(10**17) #Electron density in /cm3\n", "Na=1*(10**19) #hole density in /cm3\n", "w0=26*(10**-3)*math.log((Nd*Na)/((1.5*(10**10))**2))\n", "print\"Built-in voltage in(volts)is=\",round(w0,3),\"V\"\n", "\n", "#(d) Calculate the drain current\n", "Vd=10 #drain voltage in volt\n", "Vg=-1.5 #gate voltage in volt\n", "Vg=-1*Vg #we take only magnitude\n", "x=sqrt(((Vd+Vg+round(w0,3))/round(Vp,2))**3)\n", "x=x*2/3\n", "y=sqrt(((Vg+round(w0,3))/(round(Vp,2)))**3)\n", "y=y*2/3\n", "Id=(Vd/round(Vp,2))-x+y\n", "Id=round(Ip,2)*Id\n", "print\"The drain current (mA)is=\",round(Id,2),\"mA\" #answer is wrong in book\n", "\n", "#(e) Calculate the saturation drain current at Vg=0\n", "Vg=-1.5 #gate voltage in volt\n", "Vg=-1*Vg #we take only magnitude\n", "x=(Vg+round(w0,3))/(round(Vp,2))\n", "y=sqrt(((Vg+round(w0,3))/(round(Vp,2)))**3)\n", "y=y*2/3\n", "Idsat=(1.0/3)-x+y\n", "Idsat=round(Ip,2)*Idsat\n", "print\"The saturation drain current (mA)is=\",round(Idsat,3),\"mA\" #answer is wrong in book\n", "\n", "#(f) Calculate the cut-off frequency\n", "fc=(2*un*q*Nd*(a**2))/(math.pi*es*(L**2));\n", "fc=fc/(10**9) #in GHz\n", "print\"The cut-off frequency(Ghz)=\",round(fc,1),\"GHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The pinch-off volatge in(Volts)is= 3.06 V\n", "The pinch-off current in(mA)is= 9.8 mA\n", "Built-in voltage in(volts)is= 0.937 V\n", "The drain current (mA)is= -16.86 mA\n", "The saturation drain current (mA)is= 0.105 mA\n", "The cut-off frequency(Ghz)= 4.9 GHz\n" ] } ], "prompt_number": 41 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.2.1:pg-239" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#calculate Pinch-Off Voltage Of a MESFET\n", "\n", "a=0.1*(10**-6) #channel height in meter\n", "Nd=8*(10**23) #Electron Concetration /m3\n", "er=13.10 #relative dielectric constant\n", "es=8.854*(10**-12)*er #permittivity of GaAs in F/m\n", "q=1.6*(10**-19) #electronic charge in C\n", "Vp=(q*Nd*(a**2))/(2*es)#pinch-off voltage\n", "\n", "print\"Pinch-off volatge in(Volts)is=\",round(Vp),\"V\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pinch-off volatge in(Volts)is= 6.0 V\n" ] } ], "prompt_number": 42 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.2.2:pg-244" ] }, { "cell_type": "code", "collapsed": false, "input": [ "\n", "#(a) Calculate the pinch-off voltage\n", "a=0.1*(10**-6) #channel height in meter\n", "Nd=8*(10**23) #Electron Concetration in /m3\n", "er=13.1 #relative dielectric constant\n", "e=8.854*(10**-12)*er #permittivity of GaAs in F/m\n", "q=1.6*(10**-19) #electronic charge in C\n", "Vp=(q*Nd*(a**2))/(2*e) #pinch-off voltage\n", "\n", "print\"Pinch-off volatge in(Volts)is=\",round(Vp,2),\"V\"\n", "\n", "#(b)Calculate the velocity ratio\n", "un=0.08 #electron mobility in m2/V.s\n", "vs=2*(10**5) #saturation drift velocity in m/s\n", "L=14*(10**-6) #channel length in meter \n", "n=(Vp*un)/(vs*L)\n", "print\"The velocity ratio is=\",round(n,3)\n", "\n", "#(c) Calculate the saturation current at Vg=0\n", "L=14*(10**-6) #channel length in meter\n", "Z=36*(10**-6) #channel width in meter\n", "Ipsat=(q*Nd*un*a*Z*round(Vp,2))/(3*L)\n", "Ipsat=Ipsat*1000 #in mA\n", "print\"The saturation current at Vg=0 is=\",round(Ipsat,3),\"mA\"\n", "\n", "#(d) Calculate the drain current\n", "\n", "Vd=5 #drain voltage\n", "Vg=-2 #gate voltage\n", "Vg=-1*Vg\n", "u=sqrt((Vd+Vg)/Vp)\n", "p=sqrt((Vg)/Vp)\n", "Id=(3*((u**2)-(p**2))-2*((u**3)-(p**3)))/(1+(n*((u**2)-(p**2))))\n", "Id=Id*Ipsat\n", "print\"The drain current (mA)is=\",round(Id,2),\"mA\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "Pinch-off volatge in(Volts)is= 5.52 V\n", "The velocity ratio is= 0.158\n", "The saturation current at Vg=0 is= 4.845 mA\n", "The drain current (mA)is= 1.26 mA\n" ] } ], "prompt_number": 44 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.2.3:pg-247" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#(a) Calculate the cut-off frequency\n", "gm=0.05 #device transconductance in mho \n", "Cgs=0.60*(10**-12) #gate source capacitance in Farad\n", "fco=(gm)/(2*math.pi*Cgs) \n", "fco=fco/(10**9) #in GHz\n", "print\"The cut-off frequency(in GHz)is=\",round(fco,2),\"GHz\" \n", "\n", "#(b)Calculate the maximum operating frequency\n", "Rd=450 #drain resistance in ohms\n", "Rs=2.5 #source-gate resistance in ohms\n", "Rg=3 #gate metallization resistance in ohms\n", "Ri=2.5 #input resistance\n", "fmax=(fco/2)*sqrt(Rd/(Rs+Rg+Ri)) \n", "print\"The maximum operating frequency(in Ghz)is=\",round(fmax,2),\"GHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The cut-off frequency(in GHz)is= 13.26 GHz\n", "The maximum operating frequency(in Ghz)is= 49.74 GHz\n" ] } ], "prompt_number": 46 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.3.1:pg-251" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#Calculate the Drain Current\n", "q=1.60*(10**-19) #charge of electron in C\n", "n=5.21*(10**15) #two-dimensional electron gas density in /m2\n", "W=150*(10**-6) #gate width in meter\n", "v=2*(10**5) #electron velocity in m/sec\n", "Ids=q*n*W*v \n", "Ids=1000*Ids #in mA\n", "print\"The drain current in(mA) is=\",int(Ids),\"mA\"\n", "\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The drain current in(mA) is= 25 mA\n" ] } ], "prompt_number": 47 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.3.2:pg-253" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#(a) Calculate the conduction band-edge difference between GaAs and AlGaAs\n", "Ega=1.8 #AlGaAs bandgap in volt\n", "Egg=1.43 #GaAs bandgap in volt\n", "AEc=Ega-Egg \n", "print\"The conduction band-edge difference(in Volt) is=\",AEc,\"V\"\n", "\n", "#(b) Calculate the sesitivity of the HEMT\n", "q=1.6*(10**-19) #charge of electron in C\n", "Nd=2*(10**24) #donar concentration /m3\n", "wms=0.8 #metal-semiconductor schottky barrier potential in volt\n", "Vth=0.13 #threshold voltage in volt\n", "er=4.43 #AlGaAs dielectric constant\n", "e=er*(8.854*(10**-12)) \n", "S=-sqrt((2*q*Nd*(wms-AEc-Vth))/(e)) #sesitivity of the HEMT\n", "S=S/(10**6) \n", "S=-1*S\n", "print\"The sensitivity of the HEMT (mV/nm) is=\",int(round(S)),\"mV/nM\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The conduction band-edge difference(in Volt) is= 0.37 V\n", "The sensitivity of the HEMT (mV/nm) is= 70 mV/nM\n" ] } ], "prompt_number": 48 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.4.1:pg-260" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math\n", "#(a) Calculate the surface potential ws(inv) for strong inversion\n", "kt=26*(10**-3) \n", "Na=3*(10**17) #doping concentration in /cm3\n", "Ni=1.5*(10**10) \n", "wsinv=2*kt*math.log(Na/Ni) \n", "print\"The strong potential w(inv) for strong inversion(in volts) is=\",round(wsinv,3),\"V\"\n", "\n", "#(b)Calculate the insulator Capacitance\n", "eir=4 #relative dielectric constant of SiO2\n", "ei=8.854*(10**-12)*eir #permittivity of SiO2 in F/m\n", "d=0.01*(10**-6) #insulator depth in meter\n", "Ci=ei/d \n", "Ci=Ci*(1000) \n", "print\"The insulator Capacitance(in mF/m**2) is=\",round(Ci,2),\"mF/m2\"\n", "\n", "#(c) Calculate the threshold voltage\n", "q=1.6*(10**-19) \n", "Na=3.0*(10**23) \n", "er=11.8 \n", "e=8.854*(10**-12)*er #permittivity of SiO2 in F/m\n", "Vth=wsinv+((2/(Ci*(10**-3)))*sqrt(e*q*Na*(wsinv/2)))\n", "print\"The threshold voltage(in Volts) is=\",round(Vth,2),\"V\"\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The strong potential w(inv) for strong inversion(in volts) is= 0.874 V\n", "The insulator Capacitance(in mF/m**2) is= 3.54 mF/m2\n", "The threshold voltage(in Volts) is= 1.71 V\n" ] } ], "prompt_number": 49 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.4.2:pg-262" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#(a)Calculate the insulator capacitance\n", "eir=3.9 #constant of SiO2\n", "ei=8.854*(10**-12)*eir #permittivity of SiO2 in F/m\n", "d=0.05*(10**-6) #insulator thickness in meter\n", "Ci=ei/d \n", "print\"The insulator capacitance(in F/m**2) is=\",\"{:.2e}\".format(Ci),\"F/m2\"\n", "\n", "#(b)Calculate the saturation drain current\n", "Z=12*(10**-6) #channel depth in meter\n", "Vg=5 #gate voltage in volt\n", "Vth=0.10 #threshold voltage in volt\n", "vs=1.70*(10**5) #electron velocity in m/s\n", "Idsat=Z*round(Ci,6)*(Vg-Vth)*vs\n", "Idsat=Idsat*1000 #in mA\n", "print\"The saturation drain current(in mA) is=\",round(Idsat,2),\"mA\"\n", "\n", "#(c)Calculate the transconductance in the saturation region\n", "Z=12*(10**-6) #channel depth in meter\n", "vs=1.70*(10**5) #electron velocity in m/s\n", "gmsat=Z*Ci*vs \n", "gmsat=gmsat*10**3\n", "print\"the transconductance in the saturation region(in millimhos) is=\",round(gmsat,2),\"millimhos\" \n", "\n", "#(d)Calculate the maximum operating frequency in the saturation region\n", "vs=1.70*(10**5) \n", "L=4*(10**-6) #channel length in meter\n", "fm=vs/(2*math.pi*L) \n", "fm=fm/(10**9) #in GHz\n", "print\"The maximum operating frequency in the saturation region(in GHz) is=\",round(fm,2),\"GHz\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The insulator capacitance(in F/m**2) is= 6.91e-04 F/m2\n", "The saturation drain current(in mA) is= 6.91 mA\n", "the transconductance in the saturation region(in millimhos) is= 1.41 millimhos\n", "The maximum operating frequency in the saturation region(in GHz) is= 6.76 GHz\n" ] } ], "prompt_number": 50 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.6.1:pg-278" ] }, { "cell_type": "code", "collapsed": false, "input": [ "# Calculate the power dissipation per bit\n", "n=3 #number of phases \n", "f=10*(10**6) #clock frequency in Hertz\n", "V=10 #applied voltage in volts\n", "Qmax=0.04*(10**-12) #maximum stored charges in Coulomb\n", "p=n*f*V*Qmax \n", "p=p*(10**6) #in mW\n", "print\"The power dissipation per bit(micro watt)is=\",int(p),\"micro Watt\"" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The power dissipation per bit(micro watt)is= 12 micro Watt\n" ] } ], "prompt_number": 51 }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Eg6.6.2:pg-279" ] }, { "cell_type": "code", "collapsed": false, "input": [ "#(a)Calculate the insulator capacitance\n", "eir=3.9 #insulator relative dielectric constant\n", "ei=8.854*(10**-12)*eir #permittivity of material in F/m\n", "d=.15*(10**-6) #insulator thickness in meter\n", "Ci=ei/d \n", "Ci=Ci*(10**5) \n", "print\"The insulator capacitance(in nF/cm**2) is =\",int(round(Ci)),\"nF/cm2\" \n", "\n", "#(b)Calculate the maximum stored charges per well\n", "Nmax=2*(10**12) #electron density in /cm2\n", "q=1.6*(10**-19) #charge of electron in C\n", "A=.5*(10**-4) #insulator cross-section in cm2\n", "Qmax=Nmax*A*q \n", "Qmax=Qmax*(10**12) #in pC\n", "print\"The maximum stored charges per well(picocoulombs)is=\",int(Qmax),\"pC\"\n", "\n", "#(c) Calculate the required applied gate voltage\n", "Nmax=2*(10**12) \n", "q=1.6*(10**-19) \n", "Vg=(Nmax*q)/(Ci*10**-9) \n", "print\"The required applied gate voltage(in Volts) is=\",int(round(Vg)),\"V\"\n", "\n", "#(d)Calculate the clock frequency\n", "P=.67*(10**-3) #power dissipation allowable per bit in Watt\n", "n=3 \n", "f=P/(n*Vg*Qmax*(10**-12)) \n", "f=f/(10**6) #in MHz\n", "print\"The clock frequency(in MHz) is=\",int(f),\"MHz\" " ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ "The insulator capacitance(in nF/cm**2) is = 23 nF/cm2\n", "The maximum stored charges per well(picocoulombs)is= 16 pC\n", "The required applied gate voltage(in Volts) is= 14 V\n", "The clock frequency(in MHz) is= 1 MHz\n" ] } ], "prompt_number": 58 } ], "metadata": {} } ] }