Comtech EF Data SDM-2020 - Manual (Page 26)

SDM-2020 Satellite Modulator Revision 7
Product Data Specification MN/SDM2020M.IOM
2-4
2.1.3 M
ODULATOR
S
PECIFICATIONS
Table 2-3. Modulator Specifications
Modulator Characteristics
TX IF Output 50 to 90 and 100 to 180 MHz, 2.5 kHz steps
-20 to +5 dBm in 0.1 dB steps
(
± 0.5 dB accuracy over operating temperature range)
TX IF Impedance 75 Ω, 18 dB return loss minimum
Optional TX IF Impedance 50 Ω, 18 dB return loss minimum
IF Output Connector BNC, female
TX Spurious:
Modulated Carrier -55 dBc minimum in a 4 kHz bandwidth relative to unmodulated carrier power for
all modulated carrier power levels. The measurement bandwidth is 5 to 500 MHz
excluding
± 1.4 times the symbol rate about the carrier frequency.
TX Spurious:
Unmodulated Carrier -55 dBc minimum in a 4 kHz bandwidth, TX power level is
≤ -5 dBm. The measurement bandwidth is 5 to 500 MHz.
TX Carrier Isolation -60 dBm maximum when TX carrier = OFF
AC Line Spurious -36 dBc maximum
IF and Data Frequency Stability ± 10 ppm
TX Carrier Phase Noise
(Single Sideband)
Max dBc/Hz Offset from Carrier Frequency
-66 100 Hz
-76 1 kHz
-86 10 kHz
-96 100 kHz
-96 1 MHz
Amplitude and Phase Imbalance ± 0.2 dB, maximum
± 2°, maximum
Carrier Null (Suppression) 30 dB, minimum
Sideband Suppression 30 dB minimum, when generating a single side band
carrier (Offset Mode)
Group Delay 4 ns peak-to peak maximum to 18.75 MHz, within EN 300 421 and prEN 301 210
I/Q Delay Matching 0.5 ns difference maximum to 18.75 MHz.
Jitter Tolerance Main Card Meets ITU-T G.823 (3/93) and ITU-T G.824 (3/93)
except T1 (1.544 Mbit/s) and E1 (2.048 Mbit/s), which requires a G.703 data interface.
Jitter Transfer < 0.5 dB peaking up to the cutoff frequency, -20 dB per decade beyond cutoff.
Nominal 3 dB cutoff is 10 Hz except E3 (34.368 Mbit/s), which is 100 Hz.