Comtech EF Data KST-12025 - Manual (Page 21)

KST-12025 Ku-Band Satellite Terminal Introduction
Rev. 1 1–5
1.1.3 LNA Assembly
The LNA assembly consists of a wave guide transmit reject filter and an LNA.
The transmit reject filter provides receive system protection from transmit energy fed
back through the antenna feed system.
The LNA standard noise temperature is 120
°
K, with optional upgrades down to 80°K,
depending upon gain over temperature (G/T) requirements.
1.1.4 Outdoor Enclosure
The outdoor unit (the RFT-1225) is a weatherproof enclosure housing the following:
•
Solid State Power Amplifier (SSPA)
•
Up and down converters
•
M&C microprocessor
•
Power supply and cables which interface with an antenna subsystem
In the transmit (uplink) direction, the RFT-1225 accepts a 70 MHz IF signal, and
transmits it in the 14.0 to 14.5 GHz frequency band.
In the receive (downlink) direction, depending upon the frequency band options, the
terminal accepts an RF signal in either the full 10.95 to 12.75 GHz band, or within an
individual sub-band (10.95 to 11.7 GHz, 11.7 to 12.2 GHz, 12.25 to 12.75 GHz), and
converts the signal to 70 MHz IF output.
Power level is 25W, and is temperature-compensated for maximum stability.
The up and down converters are dual conversion, with individual synthesizers for
independent transmit and receive transponder selection.
The microprocessor provides:
•
Online loop monitoring
•
Dynamic control functions
•
Configuration control
•
Fault/status monitoring
•
Serial computer/terminal interface