In [1]:

```
import math
#Variable Declaration
d=36000 *10**3 #distance of geostationary satellite from earth's surface
Gt=100 # Antenna gain of 20dB
Pt=10 # Power radiated by earth station
#Calculation
Prd=Pt*Gt/(4*math.pi*d**2)
#Result
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))
```

In [2]:

```
import math
#Variable Declaration
c=3*10**8 #speed of light
R=10000 #path length
f=4.0 # operating frequencyin GHz
EIRP=50 #in dB
gr=20 #antenna gain in dB
rp=-120 # received power in dB
#Calculation
#(a)
lamda=c/(f*10**9)
pl=20*math.log10(4*math.pi*R/lamda)
#(b)
Lp=EIRP+gr-rp
#Result
print("(a)\n Operating wavelength = %.3f m\n Path loss(in dB) = %.2f dB"%(lamda,pl))
print("\n\n (b)\n Path loss = %.0fdB"%Lp)
```

In [3]:

```
import math
#Variable Declaration
p=75 # rotation of plane of polarization
#Polarization rotation is inversaly propotional to square of the operating frequency
f= 5.0 #frequency increased by factor
x=f**2 #rotation angle will decrease by aa factor of 25
#Calculation
k=math.pi/180.0
p_ex=p/x
Apr=-20*math.log10(math.cos(p*k))
Apr2=-20*math.log10(math.cos((p_ex)*k))
#Result
print("For polarization mismatch angle = 75°\n Attenuation = %.2f dB"%Apr)
print("\n\n For polarization mismatch angle = 3° \n Attenuation = %.3f dB"%Apr2)
```

In [7]:

```
#Variable Declaration
g1=30 #gain of RF stage in dB
t1=20 #Noise temperature in K
g2=10 #down converter gain in dB
t2=360 #noise temperature in K
g3=15 #gain of IF stage in dB
t3=1000 #noise temperature in K
t=290 #reference temperature in K
G1=1000.0 #30 dB equivalent gain
#Calculation
Te=t1+(t2/G1)+t3/(G1*g2)
F=1+Te/t
#Result
print("Effective noise temperature, Te = %.2fK"%Te)
print("\n\nSystem Noise Figure, F = %.2f"%F)
```

In [8]:

```
#Variable Declaration
g1=30 #gain of RF stage in dB
t1=20 #Noise temperature in K
g2=10 #down converter gain in dB
t2=360.0 #noise temperature in K
g3=15 #gain of IF stage in dB
t3=1000 #noise temperature in K
t=290.0 #reference temperature in K
G1=1000.0 #30 dB equivalent gain
#Calculation
F1=1+t1/t
F2=1+t2/t
F3=1+t3/t
F=F1+((F2-1)/G1)+(F3-1)/(G1*g2)
#Result
print("Noise Figure specificatios of the three stages are as follow,\n\n F1 = %.3f\n F2 = %.2f\n F3 = %.2f"%(F1,F2,F3))
print("\n\n The overall noise figure is, F = %.2f"%F)
```

In [9]:

```
import math
#Variable Declaration
L=1.778 #Loss factor of the feeder 2.5dB equivalent
ts=30 #Noise temperature of sattelite receiver in K
t=50 #Noise temperature in K
ti=290.0 # reference temperature in K
#Calculation
x=t/L
y=ti*(L-1)/L
Te=x+y+ts
F1=1+(ts/ti)
F2=1+(Te/ti)
#Result
print("contribution of antenna noise temperature when\n referred to the input of the receiver is %.1f K"%x)
print("\n\n Contribution of feeder noise when referred to the\n input of the receiver is %.1f"%y)
print("\n\n1. Noise figure in first case = %.3f = %.3f dB"%(F1,10*math.log10(F1)))#answer in book is different 0.426dB
print("\n\n2. Noise figure in second case = %.3f = %.2f dB"%(F2,10*math.log10(F2)))
```

In [10]:

```
import math
#Variable Declaration
Ta=40 #Antenna Noise temperature
Ti=290.0 #Reference temperature in K
T=50.0 #Effecitve input noise temperatuire
#Calculation
Tf=Ti
L=(Ta-Tf)/(T-Tf)
L=math.ceil(L*10**4)/10**4
#Result
print("Loss factor = %.4f = %.3f dB"%(L,10*math.log10(L)))
```

In [11]:

```
import math
#Variable Declaration
Ta=50 #Antenna Noise temperature
Tf=300 #Thermodynamic temperature of the feeder
Te=50 # Effecitve input noise temperatuire
#Calculation for (a)
Lf=1.0
T=(Ta/Lf)+(Tf*(Lf-1)/Lf)+Te
#Result for (a)
print("(a)\n System noise temperature = %.0fK"%T)
#Calculation for (b)
Lf=1.413
T=(Ta/Lf)+(Tf*(Lf-1)/Lf)+Te
#Result for (b)
print("\n\n (b)\n System noise temperature = %.3fK"%(math.ceil(T*10**3)/10**3))
```

In [14]:

```
import math
#Variable Declaration
e=35 #EIRP radiated by satellite in dBW
g=50 #receiver antenna gain in dB
e1=30 #EIRP of interfacing satellite in dBW
theeta=4 #line-of-sight between earth station and interfacing sattelite
#Calculation
x=(e-e1)+(g-32+25*math.log10(theeta))
#Result
print("carrier-to-interface (C/I) = %.2f dB"%x)
```

In [15]:

```
import math
#Variable Declaration
ea=80 #EIRP value of earth station A in dBW
eb=75 #EIRP value of earth station B in dBW
g=50 #transmit antenna gain in dB
gra=20 #receiver antenna gain for earth station A in dB
grb=15 #receiver antenna gain for earth station B in dB
theeta=4 #viewing angle of the sattelite from two earth station
#Calculation
eirp_d=eb-g+32-25*math.log10(theeta)
c_by_i=ea-eirp_d+(gra-grb)
#Result
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)
```

In [16]:

```
import math
#Variable Declaration
u=10000.0 # equivalent to 40dB
#carrier sinal strength at eart station by downlink
d=3162.28 #equivalent to 35dB
#Calculation
x=1/((1/u)+(1/d))
#Result
print("Total carrier-to-interference ratio is %.2f = %.1f dB"%(x,10*math.log10(x)))
```

In [17]:

```
import math
#Variable Declaration
theeta=5.0 #Angle form by slant ranges of two satellites
dA=42100.0*10**3 #Slant range of satellite A
dB=42000.0*10**3 #Slant range of satellite B
r=42164.0*10**3 #radius of geostationary orbit
#Calculation
beeta=((dA**2+dB**2-math.cos(theeta*math.pi/180)*2*dA*dB)/(2*r**2))
beeta=math.ceil(beeta*10**3)/10**3
beeta=(180/math.pi)*math.acos(1-beeta)
#Result
print("Longitudinal separation between two satellites is %.3f°"%beeta)
```

In [18]:

```
import math
#Variable Declaration
Ga=60.0 #Antenna Gain in dB
Ta= 60.0 #Noise teperature of Antenna
L1=1.12 #Feeder Loss equivalent to dB
T1=290.0 #Noise teperature of stage 1
G2=10**6 #Gain of stage 2 in dB
T2=140.0 #Noise teperature of stage 2
T3=10000.0 #Noise teperature of stage 3
G=Ga-0.5 #input of low noise amplifier
#Calculation
Ts=(Ta/L1)+(T1*(L1-1)/L1)+T2+(T3/G2)
Ts=math.floor(Ts*100)/100
x=G-10*math.log10(Ts)
#Result
print("Tsi = %.2fK\n\n G/T(in dB/K)= %.0f dB/K"%(Ts,x))
```

In [ ]:

```
import math
#Variable Declaration
Ga=60.0 #Amplifier Gain in dB
Ta= 60.0 #Noise teperature of Antenna
L1=1.12 #Feeder Loss equivalent to dB
T1=290.0 #Noise teperature of stage 1
G2=10**6 #Gain of stage 2 in dB
T2=140.0 #Noise teperature of stage 2
T3=10000.0 #Noise teperature of stage 3
G=Ga-0.5 #input of low noise amplifier
#Calculation
T=Ta+T1*(L1-1)+L1*(T2+(T3/G2))
x=G-10*math.log10(T)
#Result
print("T = %.1fK\n\n G/T = %.0f dB/k"%(T,math.ceil(x)))
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.")
```

In [1]:

```
import math
#Variable Declaration
f=6.0*10**9 # uplink frequency
eirp=80.0 # Earth station EIRP in dBW
r=35780.0 # Earth station satellite distance
l=2.0 # attenuation due to atomospheric factors in dB
e=0.8 # satellite antenna's aperture efficiency
a=0.5 # satellite antenna's aperture area
T=190.0 # Satellite receiver's effective noise temperature
bw=20.0*10**6 # Satellite receiver's bandwidth
cn=25.0 # received carrier-to-noise ratioin dB
c=3.0*10**8 # speed of light
#Calculation
k=1.38*10**-23
lamda=c/f
G=e*4*math.pi*a/lamda**2
G=math.ceil(G*100)/100
Gd=10*math.log10(G)
p=10*math.log10(k*T*bw)
pl=20*math.log10(4*math.pi*r*10**3/lamda)
rp=eirp-l-pl+Gd
rp=math.floor(rp*100)/100
rc=math.floor((rp-p)*100)/100
lm=rc-cn
#Result
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))
```