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3 low noise amplifier (lna), 4 outdoor enclosure – Comtech EF Data CST-5005 User Manual

Page 15

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CST-5005 C-Band Satellite Terminal

Introduction

Rev. 1

1–5

1.1.3 Low Noise Amplifier (LNA)

The feed assembly consists of an LNA and a wave guide transmit reject filter.

The transmit reject filter provides receive system protection from transmit energy fed
back through the antenna feed system.

The LNA standard noise temperature is 65

°

K, with optional upgrades down to 33°K,

depending upon gain over temperature (G/T) requirements.

1.1.4 Outdoor Enclosure

The RFT-505 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-505 accepts a 70 MHz IF signal, and transmits
it in the 5.845 to 6.425 GHz frequency band.

In the receive (downlink) direction, the terminal accepts an RF signal in the 3.620 to
4.200 GHz band, and converts the signal to 70 MHz IF output.

Power levels range from +8 dBm (for driving an external TWT) to 10W, depending upon
Equivalent Isotropically Radiated Power (EIRP) requirements.

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