290 Chapter 2
Performance Verification Tests
33. Gain Compression: Agilent E4401B, E4402B, E4403B, and E4411B
33. Gain Compression: Agilent E4401B,
E4402B, E4403B, and E4411B
This test verifies the ability of the analyzer to measure relatively
low-amplitude signals in the presence of higher-amplitude signals. Gain
compression is measured by applying two signals, separated by a
defined amount in frequency. The higher-amplitude signal is set to yield
the specified total power at the input mixer (the power at the input
mixer is defined as the input power level minus the input attenuation).
The lower-amplitude signal is set at least 35 dB below the
higher-amplitude signal, such that its power does not significantly add
to the total power. The higher-amplitude signal is turned off and the
lower-amplitude signal level is measured. This is the uncompressed
amplitude.
The higher-amplitude signal is turned on and the amplitude of the
lower-amplitude signal is again measured. This is the compressed
amplitude. The difference between the uncompressed and compressed
amplitude is the measured gain compression.
There are no related adjustment procedures for this performance test.
Equipment Required
Synthesized sweeper
Synthesized signal generator
Power meter, dual channel
RF power sensor
Directional bridge
Cable, BNC, 120-cm (48-in)
Cable, APC 3.5 (m) (2 required)
Adapter, Type-N (m) to Type-N (m)
Adapter, Type-N (m) to APC 3.5 (f) (3 required)
Adapter, Type-N (m) to SMA (m)
Additional Equipment for 75 Ω Input
Power sensor, 75 Ω
Adapter, Type-N (m), to BNC (m), 75 Ω
Adapter, mechanical, Type-N (m), 50 Ω to Type-N (f), 75 Ω
Procedure
1. Zero and calibrate the power meter and power sensor combination in
log mode (power reads out in dBm) as described in the power meter
operation manual.
2. Connect the equipment as shown in Figure 2-51, with port 1 of the