Specifications

SDM-300L3 Satellite Modem Revision 0
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 (Turbo only) • SDM-650B
• CDM-600 (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
• 8PSK
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