3A

Question 1

What is the basic transmitter path?

Answer 1

After receiving data from the DTE, the modem modulates the information into an Intermediate Frequency (IF) using the parameters assigned to access the satellite (frequency band, modulation types, data rate, etc.). From the modem, the IF is passed to the block up converter where it is translated into a usable radio frequency. The final stage in transmission is amplification at the high-power amplifier (HPA).

Question 2

The ___ primary responsibility is to translate the IF, given to it by the modem, to a usable satellite radio frequency.

Answer 2

block up converter’s

Question 3

The up converter also provides a variable amount of attenuation to the transmission frequency in order to control…?

Answer 3

total power output

Question 4

Generally, the block up converter conveys the transmit signal to the
amplifier through a…?

Answer 4

coaxial cable

Question 5

A ___ is used in communications terminals to amplify the radio frequency to a level suitable to reach the satellite, and to provide adequate signal strength for the receiving terminal.

Answer 5

high-powered amplifier (HPA)

Question 6

Amplifiers for satellite communications come in a variety of models, but the one most commonly used is…?

Answer 6

Traveling Wave Tube Amplifier (TWTA)

Question 7

TWTAs contain vacuum tubes that radio frequencies pass through. As the tube becomes ____, it amplifies the signal’s strength.

Answer 7

heated

Question 8

Other types of amplifiers include:

Answer 8

Solid State Power Amplifiers (SSPAs)and Klystron Power Amplifiers (KPAs).

Question 9

What is the basic receive path?

Answer 9

The first step is to receive a downlink radio frequency from the assigned satellite. After entering the feed horn,
the radio frequency is passed to a low noise amplifier (LNA). From there, it is translated back to an IF at the
block down converter. The IF is then passed to the modem for data extraction.

Question 10

Ground terminals often receive a weak downlink signal from the satellite due to the physical distance between the two, often ranging from:

Answer 10

-140 to -70 dbm.

Question 11

In order to bring the signal to a usable level, it is passed through a
___, where it is amplified without degrading the signal-to-noise ratio.

Answer 11

low noise amplifier (LNA)

Question 12

Much like its counterpart, the ___ is used for frequency translation.
However, instead of translating into a radio frequency it instead converts the downlink frequency into an IF. The IF then sent to the modem for data extraction.

Answer 12

block down converter