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Compatibility, Description of the modulator, Overview – Comtech EF Data SDM-300L3 User Manual

Page 26: Description

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SDM-300L3 Satellite Modem

Revision 1

Introduction

MN/SDM300L3.IOM

1–6

1.5

Compatibility

The SDM-300L3 is functionally compatible with many Comtech EF Data modems.
When properly configured, the unit will interoperate with the following Comtech EF
Data modems:

CDM-550/550T

SDM-650B

CDM-600/600L
(Open Network and Turbo only)

SDM-6000

SDM-100/100A

SDM-8000

SDM-300/300A

1.6

Description of the Modulator

1.6.1

Overview

The modulator provides PSK modulated carriers within the 950 to 1750 MHz range. The
types of modulation that encode the transmitted baseband data from the interface PCB
are:

BPSK

QPSK

OQPSK

8-PSK

1.6.2

Description

The modulator is composed of eight basic subsections. These subsections are divided into
the baseband processing section and the RF section of the modulator. The modulator
controls all programmable functions on this module. Fault information from the
modulator is sent to the M&C. Refer to Chapter 9 for a list of reported faults.

The major modulator subsections are:

Scrambler/Differential

Encoder

Convolutional

Encoder

Programmable Vector Rotation

I/Q Nyquist Filters

Modulator

RF

Synthesizer

Output

Amplifier

Output Level Control