Amplifier – Definition and Pronunciation
What is amplifier?
A (highly-linear) device used to increase the amplitude (power) of a signal. In an earth station the main amplifier is known as the High Power Amplifier (HPA). For a Very Small Aperture Terminal (VSAT) antenna, the amplifier may be included in the Block UpConverter (BUC). While a variety of power values are available, HPAs typically range from 500 to 3 000 W; BUCs range from 5–25 W for commercial applications. Other amplifiers are used throughout the earth station to amplify various stages of the signal.
Amplifier Examples
The communications payload system has a satellite forward path connecting the forward uplink to the calibration network by way of a receiver and a transmitter. The satellite forward path also typically includes frequency converters, multiplexers, demultiplexers, amplifiers, filters, and other components.
From “Aeronautical Mobility Services”.
The number of subscribers that can be served per beam is related to the reuse factor (between 25:1 and 50:1), the average bit rate desired per user, and the average EIRP per beam (EIRP is determined by the Traveling Wave Tube Amplifier (TWTA) size and the beams’ sizes, which determine the beam gains).
From “High Throughput Satellites (HTS) and KA/KU Spot Beam Technologies”.
The traditional approach is to reduce the average power at the input of the amplifier such that the maximum signal excursions are within the linear range of the amplifier characteristic. This reduction is termed power backoff and, as defined earlier, can be significant for BW-efficient systems.
From “DVB-S2 Modulation Extensions and Other Advances”.