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//Chapter 15: Antennas for Special Applications
//Example 15-20.2
clc;
//Variable Initialization
f = 1.6e9 //Frequency (Hz)
r = 1400e3 //Height (m)
r_sep = 3500e3 //Height for 10 degree seperation (m)
c = 3e8 //Speed of light(m/s)
Ta = 300 //Satellite antenna temperature (K)
Tr = 45 //Satellite receiver temperature (K)
k = 1.3e-23 //Boltzmann's constant (J/K)
bandwidth = 9.6e3 //Bandwidth (Hz)
snr = 6 //Signal to noise ratio (dB)
rcp_gain = 3 //Helix gain(dB)
beam_angle = 25 //RCP spot beam (degree)
Tsky = 6 //Sky Temperature (K)
Tr_handheld = 75 //Hand held receiver temperature (K)
//Calculations
wave_lt = c/f //Wavelength (m)
Ld = (wave_lt/(4*%pi*r))**2
Ld = 10*log10(Ld) //Propagation loss factor (dB)
sat_gain = 40000/(beam_angle**2)
sat_gain = 10*log10(sat_gain) //Satellite gain (dB)
Tsys = Ta+Tr //System temperature (K)
N = k*Tsys*bandwidth //Noise power (W)
N_db = 10*log10(N) //Noise power (dB)
Pt_up = snr - (rcp_gain) - (sat_gain) + N_db - Ld //Uplink power (dB)
Pt_up = 10**(Pt_up/10) //Uplink power (W)
Ta_quad = 0.85*(Tsky) + 0.15*(Ta) //Downlink antenna temperature (K)
Tsys_quad = Ta_quad + Tr_handheld //System temperature(K)
N_quad = k*Tsys_quad*bandwidth //Noise power (W)
N_quad_db = 10*log10(N_quad) //Noise power (dB)
Pt_down = snr - (rcp_gain) - (sat_gain) + round(N_quad_db) - round(Ld) //Downlink power (dB)
Pt_down = 10**(Pt_down/10) //Downlink power (W)
Ld_sep = (wave_lt/(4*%pi*r_sep))**2
Ld_sep = 10*log10(Ld_sep) //Propagation loss factor(dB)
Pt_sep = snr - (rcp_gain) - sat_gain + ceil(N_db) - round(Ld_sep) //Uplink power (dB)
Pt_sep = 10**(Pt_sep/10) //Uplink power (W)
//Results
mprintf( "The Satellite gain is %.1f dB",sat_gain)
mprintf( "\nThe Uplink power required is %.3f W", Pt_up)
mprintf( "\nThe Downlink power required is %.4f W",Pt_down)
mprintf( "\nThe Uplink power required for 10 deg. from horizon is %.3f W",Pt_sep)
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