SSPI Satellite Communications Technologies & Systems 3

Question 1

In a satellite link budget, the figure of merit G/T represents:

Accepted Answer

Receive antenna gain divided by system noise temperature

Answer

G/T is the receive antenna gain (dBi) minus the system noise temperature (dBK), a key metric for evaluating earth station receive performance.

Question 2

Which orbital slot phenomenon requires geostationary satellites to perform regular north-south station-keeping maneuvers?

Accepted Answer

Lunar and solar gravitational perturbations causing inclination changes

Answer

Lunar and solar gravity cause the orbital plane to tilt (inclination), requiring north-south station-keeping burns typically consuming most of the satellite's propellant budget.

Question 3

A bent-pipe transponder in a communications satellite differs from an on-board processing (OBP) transponder in that it:

Accepted Answer

Simply amplifies and frequency-shifts the signal without demodulation

Answer

A bent-pipe transponder is a frequency translator and amplifier only; OBP transponders demodulate, process, and re-modulate, enabling more flexible routing.

Question 4

The Nyquist bandwidth of a satellite carrier is most closely related to:

Accepted Answer

The symbol rate of the modulated signal

Answer

The minimum (Nyquist) bandwidth equals the symbol rate (baud rate), so a 36 Msps signal requires at least 36 MHz of transponder bandwidth.

Question 5

What is the function of a Low-Noise Block downconverter (LNB) in a satellite receive system?

Accepted Answer

Amplifies and downconverts the satellite signal with minimal added noise

Answer

The LNB amplifies the weak satellite signal and converts it from Ku/Ka band to a lower IF frequency (950–2,150 MHz) for transmission over coaxial cable.

(SSPI) Society of Satellite Professionals International Certification Practice Test

(SSPI) Society of Satellite Professionals International Certification Practice Test

SSPI Satellite Communications Technologies & Systems 3