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2 technology, 3 reliability, 4 construction – Comtech EF Data LNB User Manual

Page 14: 5 functional description

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LNB Low-Noise Block Downconverter

Revision 0

Introduction

MN-LNB

1–2

1.2

Technology

The amplifiers incorporate both HEMT (High Electron Mobility Transistors) devices for Low-
Noise temperature performance and GaAs FET (Gallium Arsenide) devices for low
intermodulation. The unit uses surface mounted components for robotic manufacturing
techniques, thereby insuring maximum product consistency and enhanced reliability.

1.3

Reliability

The Comtech EF Data LNB series utilizes proprietary circuitry and high quality components to
achieve an MTBF (mean time between failures) in excess of 160,000 hours. Each unit is
subjected to a 72 hour burn-in and temperature cycled from -40 to 140

°F

(-40 to +60

°C).

1.4

Construction

The LNB is housed in a waterproof enclosure with a small profile to better accommodate
redundancy configurations. The enclosure also provides a pressurizable, integral waveguide
flange.

1.5

Functional Description

Features:

Flexible configuration

Low phase noise - Meets or exceeds MIL-188-165A

Noise Figure options

Gain options

Output power options

Transmit Reject options

Optional Fault Reporting

Mates directly to LPOD family of BUCs for DC supply, 10MHz source

Optional 1:1 Redundancy


The LNB is a field-interchangeable block downconverter module that translates a band-specific
frequency block, in this case, X-Band, from the antenna down to L-Band (950 to 1450 MHz).

The LNB requires a +12 to +24VDC source and high stability 10MHz reference source supplied
via coaxial cable with external tri-plexer. DC power can be supplied via optional 4 or 6 pin
connector with 10MHz reference delivered via external di-plexer.

10 MHz reference should provide sinewave output at 0, +-5dBm.
Reference phase noise:

<-125 dBc 10Hz

<-152 dBc 100Hz

<-160 dBc 1KHz

<-165 dBc >10KHz