Comtech EF Data SDM-9000, Installation And Operation Manual

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Theory of Operation SDM-9000 Satellite Modem
5–6 Rev. 4
5.2.2 Specifications
Modulation Types
•
QPSK
•
8PSK (optional)
•
16QAM (optional)
Data Rate Range 6.0 to 52.0 Mbit/s (Four data rate plug-on module)
Symbol Rate Range 1.7 to 37.6 Ms/s
Frequency Range 50 to 180 MHz
Frequency Select Method Synthesized
Frequency Step Size 2.5 kHz
Frequency Stability Internal Reference:
±
10 PPM oscillator
0.2 PPM high stability option
External Reference (supported with High Stability
Option):
Will lock to external 5, 10, or 20 MHz reference
Phase Error 2.0° maximum
Filtering Type Nyquist, pre-equalized
Spectral Occupancy
Spectral density is -30 dB at
±
0.75 symbol rate
Spurious and Harmonics -55 dBc
Output Power -20 to +5 dBm, in 0.1 dB steps
Output Power Stability
±
0.5 dB
Output Power Adjustment 0.1 dB step size
Output Impedance 75
Ω
(50
Ω
optional)
Output Return Loss > 18 dB
Differential Encoding 2-phase or none
FEC Encoding
•
Convolutional, K = 7
•
QPSK rates 1/2, 3/4, 7/8
•
8PSK rates 2/3, 5/6 (Trellis)
•
16QAM rates 3/4, 7/8
I/O Connector 96-pin DIN
Reported Faults
•
IF Synthesizer
•
Data Clock Activity
•
Data Clock Synthesizer
•
I Channel Activity
•
Q Channel Activity
•
AGC Level
•
External SCT Synthesizer
•
External Reference Activity