Modulator Spurious Emissions; Modulator Phase Noise; Modulator If Output Spectrum Shape; L-Band Inmarsat Spurious Emissions - Comtech EF Data SNM-1001L Installation And Operation Manual

SNM-1001L Satellite Modem
Specifications
A.5.5

Modulator Spurious Emissions

Spurious emissions are measured relative to the power of an unmodulated carrier. The
measurement is done with the carrier on in continuous mode and modulated by the correct
data/clock signal. Spurious emissions measured in a 4 kHz bandwidth at the TX IF output
are –55 dBc from 55 MHz to 2 GHz.
A.5.6

Modulator Phase Noise

1. The phase noise of the TX IF output carrier is no worse than:
2. Fundamental AC line spurious is -42 dBc or lower.
3. The sum of all the single sideband spurious, from 0 to 0.75 x symbol rate, is -42 dBc
or lower.
A.5.7

Modulator IF Output Spectrum Shape

The modem meets the following TX output spectral mask specifications. The desired
mask is selectable from the front panel or remotely.
•
•
•
•
A.5.8

L-Band INMARSAT Spurious Emissions

Note: The item below may require a special VCO to meet the specification. If so, an
optional "INMARSAT" version will be generated and the Inmarsat Emissions is added to
the Future Items list. This may require operation at a lower transmit power level. Outside
of 1610 to 1680 MHz the requirements are the same as the L-Band Spurious Emissions
requirement. When operated over the Inmarsat frequency range of 1626 to 1660 MHz the
spurious emissions in a range from 1610 to 1680 MHz are ≥ -60 dBc.
dBc/Hz
-63.0 100 Hz
-73.0 1 kHz
-83.0 10 kHz
-93.0 100 kHz
INTELSAT/EUTELSAT
Closed net (CEFD and CSC)
Closed net (Fairchild compatible)
Closed net (SDM 51, SDM 52)
Distance from Carrier
A–8
Revision 1
MN/SNM1001L.IOM