Comtech EF Data PCB-4300 - Manual (Page 20)

PCB-4300 1:2 Phase Combiner Revision 2
Introduction MN/PCB4300.IOM
1–6
1.3.3 System Gain
Note that, due to the power divider and cable losses, the overall gain of the system will be
approximately 5-10 dB less than the individual gain of each amplifier. Refer to the system test
data sheet for actual system gain.
1.3.4 System Attenuation
The PCB-4300 makes it easy to adjust the overall system gain. In a standard 1:2 phase combined
system, there is no common attenuator to adjust the overall system gain; the gains of each of the
individual SSPAs must be changed appropriately. The PCB-4300 eases this process: The user
need only input a single desired attenuation value via the ATT attenuation command (see
Appendix B. REMOTE CONTROL), and the PCB-4300 automatically communicates with
each SSPA and adjusts the individual gains accordingly, resulting in the desired attenuation value
while maintaining optimum power combining conditions.
The SSPAs included in the system are calibrated over a range 10 dB beyond specification (30 dB
vs. 20 dB). As explained above, a portion of the 30 dB range is required for gain equalization;
therefore, while the maximum allowable attenuation in a 1:2 system is software-limited to 24 dB,
it still exceeds system specifications.