Comtech EF Data PCB-4300 - Manual (Page 35)

PCB-4300 1:2 Phase Combiner Revision 2
Operation and Adjustment Procedures MN/PCB4300.IOM
3–5
3.3 System Verification
For this section, it is assumed that the system has been assembled and all cables have been
connected per the previous section, and that the output port is terminated in a high power load as
depicted in the block diagram in Figure 1-2.
The following test equipment is required
• Dual Channel Power Meter, or two single channel Power Meters. (If only one power
meter is available, attachment to the Combined Output Power Test Port Coupler is
generally preferred.)
• CW Input Signal Source.
• Calibration data of system test couplers, i.e., the Combined Output Power Coupler and
the “Wasted” Power Coupler.
• PC for serial control and communication.
• Test Datasheet (shipped from by factory).
Overall system performance may essentially be verified by repeating the factory-performed tests,
and then comparing these new results to the findings on the provided Test Datasheet. Take care to
review and become familiar with this datasheet before attempting these tests.
Observe the following:
Step Procedure
1 Verify that the amplitude offsets reported by the PCB-4300 agree with those set at the
factory (see provided Test Datasheet). The offsets for SSPAs #1, #2 and #3 can be
queried by sending remote query via the serial port (where X=PCB-4300
address, and Y=1, 2, or 3 – the individual SSPA offset in question). Make sure the
system attenuation is set to zero (ATT=0.00).
After the amplitude offsets have been verified in Step 1, the procedure is then basically continued
in two parts – System Gain Verification and System P1dB Verification. To continue:
3.3.1 System Gain Verification
Step Procedure
2
Set the CW Input Signal Source to the start, center, and end frequencies of the
amplifier range and to a level that will give a system output power of approximately 10
dB below the combined P1dB.
For example, for a 14-14.5 GHz system with a combined Prated of 53dBm (individual
SSPA= 50dBm) and a system gain of 65 dB, the input source would be set to a level of 53
dBm – 65 – 10 = -22 dBm.
Measure, verify, and record this level at the input to the phase combiner system for
each of the three frequencies.
3 Attach one channel of the power meter to the Combined Output Power Test Coupler
(refer to Figure 3-1); attach the second channel of the power meter to the “Wasted”
Power Test Coupler. Make sure the power meter has been appropriately calibrated to
include the respective correction factors of the test port couplers.