Telecommunications Satellite Communications 3

Question 1

What is a 'link budget' in satellite communications?

Accepted Answer

A calculation of all signal gains and losses along a satellite communication path

Answer

A link budget accounts for all gains (antenna gain, amplifier power) and losses (free-space path loss, atmospheric attenuation) to determine whether a satellite link has sufficient signal-to-noise margin.

Question 2

EIRP (Effective Isotropic Radiated Power) is calculated as the product of:

Accepted Answer

Transmitter power and antenna gain

Answer

EIRP = Transmitter Power × Antenna Gain, and it represents the equivalent power an isotropic antenna would need to radiate to achieve the same signal strength in the direction of the beam.

Question 3

Which technique transmits two independent signals on the same frequency using orthogonal signal polarizations (e.g., horizontal and vertical) to double satellite capacity?

Accepted Answer

Polarization frequency reuse

Answer

Polarization frequency reuse exploits the fact that orthogonally polarized signals do not interfere with each other, allowing the same frequency band to carry two separate signals and effectively doubling capacity.

Question 4

Adjacent Satellite Interference (ASI) in the geostationary arc is caused by:

Accepted Answer

Signals from nearby satellites being captured along with the intended satellite's signal

Answer

ASI occurs when the antenna beam of a nearby satellite in the geostationary arc overlaps the receive pattern of a ground station, introducing an unwanted signal alongside the intended one.

Question 5

The G/T ratio used to characterize satellite receiver performance stands for:

Accepted Answer

Gain-to-Noise Temperature ratio

Answer

G/T (Gain-to-Noise Temperature) is a figure of merit for a satellite earth station receiver; a higher G/T means the station is better at detecting weak signals relative to its own internal noise.

Telecommunications Practice Test

Telecommunications Practice Test

Telecommunications Satellite Communications 3