{
"metadata": {
"name": "",
"signature": "sha256:d8e48debe58189bda0ba7970010a7f3d133d055f445572e1b90b2e8739a1cc2b"
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"chapter 7: Satellite Link Design Fundamentals"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.1, page no-249"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"d=36000 *10**3 #distance of geostationary satellite from earth's surface\n",
"Gt=100 # Antenna gain of 20dB\n",
"Pt=10 # Power radiated by earth station\n",
"\n",
"#Calculation\n",
"Prd=Pt*Gt/(4*math.pi*d**2)\n",
"\n",
"\n",
"#Result\n",
"print(\"Prd = %.4f * 10 ^-12 W/m^2\\nPower received by the receiving antenna is given by Pr = %.3f pW\"%(Prd*10**12,Prd*10**13))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Prd = 0.0614 * 10 ^-12 W/m^2\n",
"Power received by the receiving antenna is given by Pr = 0.614 pW\n"
]
}
],
"prompt_number": 1
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.2, page no-262"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#Variable Declaration\n",
"c=3*10**8 #speed of light \n",
"R=10000 #path length\n",
"f=4.0 # operating frequencyin GHz\n",
"EIRP=50 #in dB\n",
"gr=20 #antenna gain in dB\n",
"rp=-120 # received power in dB\n",
"\n",
"\n",
"#Calculation\n",
"\n",
"#(a)\n",
"lamda=c/(f*10**9)\n",
"pl=20*math.log10(4*math.pi*R/lamda)\n",
"\n",
"#(b)\n",
"Lp=EIRP+gr-rp\n",
"\n",
"\n",
"#Result\n",
"print(\"(a)\\n Operating wavelength = %.3f m\\n Path loss(in dB) = %.2f dB\"%(lamda,pl))\n",
"print(\"\\n\\n (b)\\n Path loss = %.0fdB\"%Lp)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a)\n",
" Operating wavelength = 0.075 m\n",
" Path loss(in dB) = 124.48 dB\n",
"\n",
"\n",
" (b)\n",
" Path loss = 190dB\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.3, page no-262"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"p=75 # rotation of plane of polarization\n",
"\n",
"#Polarization rotation is inversaly propotional to square of the operating frequency\n",
"\n",
"f= 5.0 #frequency increased by factor \n",
"x=f**2 #rotation angle will decrease by aa factor of 25\n",
"\n",
"\n",
"#Calculation\n",
"k=math.pi/180.0\n",
"p_ex=p/x\n",
"Apr=-20*math.log10(math.cos(p*k))\n",
"Apr2=-20*math.log10(math.cos((p_ex)*k))\n",
"\n",
"\n",
"#Result\n",
"print(\"For polarization mismatch angle = 75\u00b0\\n Attenuation = %.2f dB\"%Apr)\n",
"print(\"\\n\\n For polarization mismatch angle = 3\u00b0 \\n Attenuation = %.3f dB\"%Apr2)"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"For polarization mismatch angle = 75\u00b0\n",
" Attenuation = 11.74 dB\n",
"\n",
"\n",
" For polarization mismatch angle = 3\u00b0 \n",
" Attenuation = 0.012 dB\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.4, page no-270"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable Declaration\n",
"g1=30 #gain of RF stage in dB\n",
"t1=20 #Noise temperature in K\n",
"g2=10 #down converter gain in dB\n",
"t2=360 #noise temperature in K\n",
"g3=15 #gain of IF stage in dB\n",
"t3=1000 #noise temperature in K\n",
"t=290 #reference temperature in K\n",
"G1=1000.0 #30 dB equivalent gain\n",
"\n",
"\n",
"#Calculation\n",
"Te=t1+(t2/G1)+t3/(G1*g2)\n",
"F=1+Te/t\n",
"\n",
"\n",
"#Result\n",
"print(\"Effective noise temperature, Te = %.2fK\"%Te)\n",
"print(\"\\n\\nSystem Noise Figure, F = %.2f\"%F)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Effective noise temperature, Te = 20.46K\n",
"\n",
"\n",
"System Noise Figure, F = 1.07\n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.5, page no-271"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"#Variable Declaration\n",
"g1=30 #gain of RF stage in dB\n",
"t1=20 #Noise temperature in K\n",
"g2=10 #down converter gain in dB\n",
"t2=360.0 #noise temperature in K\n",
"g3=15 #gain of IF stage in dB\n",
"t3=1000 #noise temperature in K\n",
"t=290.0 #reference temperature in K\n",
"G1=1000.0 #30 dB equivalent gain\n",
"\n",
"\n",
"#Calculation\n",
"F1=1+t1/t\n",
"F2=1+t2/t\n",
"F3=1+t3/t\n",
"F=F1+((F2-1)/G1)+(F3-1)/(G1*g2)\n",
"\n",
"\n",
"#Result\n",
"print(\"Noise Figure specificatios of the three stages are as follow,\\n\\n F1 = %.3f\\n F2 = %.2f\\n F3 = %.2f\"%(F1,F2,F3))\n",
"print(\"\\n\\n The overall noise figure is, F = %.2f\"%F)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Noise Figure specificatios of the three stages are as follow,\n",
"\n",
" F1 = 1.069\n",
" F2 = 2.24\n",
" F3 = 4.45\n",
"\n",
"\n",
" The overall noise figure is, F = 1.07\n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.6, page no-272"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"L=1.778 #Loss factor of the feeder 2.5dB equivalent\n",
"ts=30 #Noise temperature of sattelite receiver in K\n",
"t=50 #Noise temperature in K\n",
"ti=290.0 # reference temperature in K\n",
"\n",
"\n",
"#Calculation\n",
"x=t/L\n",
"y=ti*(L-1)/L\n",
"Te=x+y+ts\n",
"F1=1+(ts/ti)\n",
"F2=1+(Te/ti)\n",
"\n",
"\n",
"#Result\n",
"print(\"contribution of antenna noise temperature when\\n referred to the input of the receiver is %.1f K\"%x)\n",
"print(\"\\n\\n Contribution of feeder noise when referred to the\\n input of the receiver is %.1f\"%y)\n",
"print(\"\\n\\n1. Noise figure in first case = %.3f = %.3f dB\"%(F1,10*math.log10(F1)))#answer in book is different 0.426dB\n",
"print(\"\\n\\n2. Noise figure in second case = %.3f = %.2f dB\"%(F2,10*math.log10(F2)))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"contribution of antenna noise temperature when\n",
" referred to the input of the receiver is 28.1 K\n",
"\n",
"\n",
" Contribution of feeder noise when referred to the\n",
" input of the receiver is 126.9\n",
"\n",
"\n",
"1. Noise figure in first case = 1.103 = 0.428 dB\n",
"\n",
"\n",
"2. Noise figure in second case = 1.638 = 2.14 dB\n"
]
}
],
"prompt_number": 9
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.7, page no-272"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"Ta=40 #Antenna Noise temperature\n",
"Ti=290.0 #Reference temperature in K\n",
"T=50.0 #Effecitve input noise temperatuire\n",
"\n",
"#Calculation\n",
"Tf=Ti\n",
"L=(Ta-Tf)/(T-Tf)\n",
"L=math.ceil(L*10**4)/10**4\n",
"\n",
"#Result\n",
"print(\"Loss factor = %.4f = %.3f dB\"%(L,10*math.log10(L)))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Loss factor = 1.0417 = 0.177 dB\n"
]
}
],
"prompt_number": 10
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.8, page no-273"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"Ta=50 #Antenna Noise temperature\n",
"Tf=300 #Thermodynamic temperature of the feeder\n",
"Te=50 # Effecitve input noise temperatuire\n",
"\n",
"\n",
"#Calculation for (a)\n",
"Lf=1.0\n",
"T=(Ta/Lf)+(Tf*(Lf-1)/Lf)+Te\n",
"\n",
"#Result for (a)\n",
"print(\"(a)\\n System noise temperature = %.0fK\"%T)\n",
"\n",
"#Calculation for (b)\n",
"Lf=1.413\n",
"T=(Ta/Lf)+(Tf*(Lf-1)/Lf)+Te\n",
"\n",
"#Result for (b)\n",
"print(\"\\n\\n (b)\\n System noise temperature = %.3fK\"%(math.ceil(T*10**3)/10**3))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"(a)\n",
" System noise temperature = 100K\n",
"\n",
"\n",
" (b)\n",
" System noise temperature = 173.072K\n"
]
}
],
"prompt_number": 11
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.9, page no-278"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"e=35 #EIRP radiated by satellite in dBW\n",
"g=50 #receiver antenna gain in dB\n",
"e1=30 #EIRP of interfacing satellite in dBW\n",
"theeta=4 #line-of-sight between earth station and interfacing sattelite\n",
"\n",
"\n",
"#Calculation\n",
"x=(e-e1)+(g-32+25*math.log10(theeta))\n",
"\n",
"\n",
"#Result\n",
"print(\"carrier-to-interface (C/I) = %.2f dB\"%x)\n",
"\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"carrier-to-interface (C/I) = 38.05 dB\n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.10, page no-279"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"ea=80 #EIRP value of earth station A in dBW\n",
"eb=75 #EIRP value of earth station B in dBW\n",
"g=50 #transmit antenna gain in dB\n",
"gra=20 #receiver antenna gain for earth station A in dB\n",
"grb=15 #receiver antenna gain for earth station B in dB\n",
"theeta=4 #viewing angle of the sattelite from two earth station\n",
"\n",
"\n",
"#Calculation\n",
"eirp_d=eb-g+32-25*math.log10(theeta)\n",
"c_by_i=ea-eirp_d+(gra-grb)\n",
"\n",
"\n",
"#Result\n",
"print(\"carrier-to-interference ratio at the satellite due to\\n inteference caused by Eart station B is, (C/I) = %.0f dB \"%c_by_i)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"carrier-to-interference ratio at the satellite due to\n",
" inteference caused by Eart station B is, (C/I) = 43 dB \n"
]
}
],
"prompt_number": 15
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.11, page no-279"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"\n",
"\n",
"u=10000.0 # equivalent to 40dB\n",
"\n",
"#carrier sinal strength at eart station by downlink \n",
"d=3162.28 #equivalent to 35dB\n",
"\n",
"\n",
"#Calculation\n",
"x=1/((1/u)+(1/d))\n",
"\n",
"\n",
"#Result\n",
"print(\"Total carrier-to-interference ratio is %.2f = %.1f dB\"%(x,10*math.log10(x)))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Total carrier-to-interference ratio is 2402.53 = 33.8 dB\n"
]
}
],
"prompt_number": 16
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.12, Page no.280"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"theeta=5.0 #Angle form by slant ranges of two satellites\n",
"dA=42100.0*10**3 #Slant range of satellite A\n",
"dB=42000.0*10**3 #Slant range of satellite B\n",
"r=42164.0*10**3 #radius of geostationary orbit\n",
"\n",
"\n",
"#Calculation\n",
"beeta=((dA**2+dB**2-math.cos(theeta*math.pi/180)*2*dA*dB)/(2*r**2))\n",
"beeta=math.ceil(beeta*10**3)/10**3\n",
"beeta=(180/math.pi)*math.acos(1-beeta)\n",
"\n",
"#Result\n",
"print(\"Longitudinal separation between two satellites is %.3f\u00b0\"%beeta)\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Longitudinal separation between two satellites is 5.126\u00b0\n"
]
}
],
"prompt_number": 17
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.13, Page no.281"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"\n",
"#Variable Declaration\n",
"Ga=60.0 #Antenna Gain in dB\n",
"Ta= 60.0 #Noise teperature of Antenna\n",
"L1=1.12 #Feeder Loss equivalent to dB\n",
"T1=290.0 #Noise teperature of stage 1\n",
"G2=10**6 #Gain of stage 2 in dB\n",
"T2=140.0 #Noise teperature of stage 2\n",
"T3=10000.0 #Noise teperature of stage 3\n",
"G=Ga-0.5 #input of low noise amplifier\n",
"\n",
"\n",
"#Calculation\n",
"Ts=(Ta/L1)+(T1*(L1-1)/L1)+T2+(T3/G2)\n",
"Ts=math.floor(Ts*100)/100\n",
"x=G-10*math.log10(Ts)\n",
"\n",
"#Result\n",
"print(\"Tsi = %.2fK\\n\\n G/T(in dB/K)= %.0f dB/K\"%(Ts,x))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Tsi = 224.65K\n",
"\n",
" G/T(in dB/K)= 36 dB/K\n"
]
}
],
"prompt_number": 18
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.14, Page no.282"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"\n",
"#Variable Declaration\n",
"Ga=60.0 #Amplifier Gain in dB\n",
"Ta= 60.0 #Noise teperature of Antenna\n",
"L1=1.12 #Feeder Loss equivalent to dB\n",
"T1=290.0 #Noise teperature of stage 1\n",
"G2=10**6 #Gain of stage 2 in dB\n",
"T2=140.0 #Noise teperature of stage 2\n",
"T3=10000.0 #Noise teperature of stage 3\n",
"G=Ga-0.5 #input of low noise amplifier\n",
"\n",
"\n",
"#Calculation\n",
"T=Ta+T1*(L1-1)+L1*(T2+(T3/G2))\n",
"x=G-10*math.log10(T)\n",
"\n",
"\n",
"#Result\n",
"print(\"T = %.1fK\\n\\n G/T = %.0f dB/k\"%(T,math.ceil(x)))\n",
"print(\"\\n\\n It is evident from the solutions of the problems 13 and 14\\n that G/T ratio is invarient regardless of the reference point in agreement \\n with a statement made earlier in the text.\")\n"
],
"language": "python",
"metadata": {},
"outputs": []
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 7.15, Page no.286"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"import math\n",
"#Variable Declaration\n",
"f=6.0*10**9 # uplink frequency\n",
"eirp=80.0 # Earth station EIRP in dBW\n",
"r=35780.0 # Earth station satellite distance\n",
"l=2.0 # attenuation due to atomospheric factors in dB\n",
"e=0.8 # satellite antenna's aperture efficiency\n",
"a=0.5 # satellite antenna's aperture area\n",
"T=190.0 # Satellite receiver's effective noise temperature \n",
"bw=20.0*10**6 # Satellite receiver's bandwidth\n",
"cn=25.0 # received carrier-to-noise ratioin dB\n",
"c=3.0*10**8 # speed of light\n",
"\n",
"#Calculation\n",
"k=1.38*10**-23\n",
"lamda=c/f\n",
"G=e*4*math.pi*a/lamda**2\n",
"G=math.ceil(G*100)/100\n",
"Gd=10*math.log10(G)\n",
"p=10*math.log10(k*T*bw)\n",
"pl=20*math.log10(4*math.pi*r*10**3/lamda)\n",
"rp=eirp-l-pl+Gd\n",
"rp=math.floor(rp*100)/100\n",
"rc=math.floor((rp-p)*100)/100\n",
"lm=rc-cn\n",
"\n",
"#Result\n",
"print(\"Satellite Antenna gain, G = %.2f = %.2f dB \\n Receivers Noise Power = %.1f dB\\n free-space path loss = %.2f dB \\n received power at satellite = %.2f dB \\n receiver carrier = %.2f is stronger than noise.\\n It is %.2f dB more than the required threshold value.\\n Hence, link margin = %.2f dB\"%(G,Gd,p,pl,rp,rc,lm,lm))\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Satellite Antenna gain, G = 2010.62 = 33.03 dB \n",
" Receivers Noise Power = -132.8 dB\n",
" free-space path loss = 199.08 dB \n",
" received power at satellite = -88.05 dB \n",
" receiver carrier = 44.75 is stronger than noise.\n",
" It is 19.75 dB more than the required threshold value.\n",
" Hence, link margin = 19.75 dB\n"
]
}
],
"prompt_number": 1
}
],
"metadata": {}
}
]
}