394 Chapter 2
Performance Verification Tests
54. Comms Frequency Response (Option BAC or BAH)
54. Comms Frequency Response (Option BAC
or BAH)
This test measures the analyzer amplitude error as a function of
frequency. The output of a source is fed through a power splitter to a
power sensor and the analyzer. The source’s power level is adjusted at
50 MHz to place the displayed signal at the analyzer center graticule
line. The power meter is then set to measure dB relative to the power
level at 50 MHz. At each new analyzer source frequency and center
frequency, the source power level is adjusted to place the signal at the
center horizontal graticule line. The power meter displays the inverse of
the frequency response relative to 50 MHz.
For improved amplitude accuracy in the PCS and Cellular bands, a
power splitter is characterized using a second power sensor (the
“reference” sensor) connected to one power splitter output port. The
other power splitter output port connects to the “buried” sensor; it is not
removed from the power splitter. Once the characterization is done, the
reference sensor is removed and replaced by the analyzer.
This procedure also tests frequency response with the optional
preamplifier (Option 1DS) turned on if the analyzer is equipped with
Option 1DS. When testing the preamplifier, it is necessary to
re-characterize the power splitter/buried sensor combination.
The related adjustment for this performance test is “Frequency
Response.”
NOTE There is no performance test record provided for recording the results of
this test. Results of this test are required by test 59. Comms Absolute
Power Accuracy (Options BAC or BAH), located in this chapter.
There are no related adjustment procedures for this performance test.
Equipment Required
Synthesized sweeper
Function generator
Power meter
RF Power sensor (2 required)
Microwave power sensor
Microwave power splitter
Adapter, APC 3.5 (f) to APC 3.5 (f)
Adapter, Type-N (m) to Type-N (m)
Adapter, Type-N (m) to BNC (f)
Fixed Attenuator, 20 dB
BNC Tee (BNC f,m,f)
Cable, BNC, 122-cm (48-in) (2 required)