SBCA Satellite Theory & Signal Transmission 2

Question 1

What is the primary advantage of using Ku-band frequencies over C-band for direct-to-home (DTH) satellite broadcasting?

Accepted Answer

Smaller dish antennas are required

Answer

Ku-band's shorter wavelength allows smaller receiving dishes (typically 45–90 cm) compared to C-band's larger 1.8–3 m dishes, making DTH practical for residential installations.

Question 2

In satellite communications, EIRP stands for Equivalent Isotropic Radiated Power. What two factors determine EIRP?

Accepted Answer

Transmit power and antenna gain

Answer

EIRP = transmit power (in watts or dBW) multiplied by the antenna gain, representing the effective power radiated in a given direction.

Question 3

Which orbital parameter describes the point in a satellite's elliptical orbit where it is closest to Earth?

Accepted Answer

Perigee

Answer

Perigee is the closest point to Earth in an elliptical orbit, while apogee is the farthest point.

Question 4

A satellite transponder with a 36 MHz bandwidth operating in bent-pipe mode retransmits signals without which process?

Accepted Answer

On-board signal regeneration or demodulation

Answer

Bent-pipe transponders perform frequency conversion and amplification but do NOT demodulate or regenerate the signal; regenerative (processing) transponders do.

Question 5

What phenomenon causes satellite signals to experience a rotation of polarization as they pass through the ionosphere?

Accepted Answer

Faraday rotation

Answer

Faraday rotation occurs when electromagnetic waves interact with free electrons in the ionosphere in the presence of Earth's magnetic field, rotating the polarization plane.

(SBCA) Satellite Broadcasting and Communications Association Certification Practice Test

(SBCA) Satellite Broadcasting and Communications Association Certification Practice Test

SBCA Satellite Theory & Signal Transmission 2