Receiver Compression Test - Keysight N5224A Service Manual

Tests and Adjustments
Performance Tests

Receiver Compression Test

Function of the Test: To measure the compression at the analyzer's specified maximum power level for the
receivers.
Specification Tested: Test Port Input–Maximum Test Port Input Level
Equipment Used:
• U3070AK01 or Z5623A Option K01 Compression Test Set
• Power meter
• Power sensors
• Two test cables
• Calibration kit
• 10-dB and 20-dB pads if the analyzer does not have an internal step attenuator
Description of the Test:
For most analyzer models, the receiver compression level is higher than the maximum source output power.
Therefore, an external amplifier is required. This test also requires that two attenuators be switched in and
out of the RF path. These requirements are met with the use of the Compression Test Set. The procedure
outlined here is for those models which require the test set.
1. The analyzer is Preset. The two test set output attenuators are set to 0 dB.
2. The analyzer is set up for a 201 point CW transmission measurement for the port pair to be tested with
the specified IF bandwidth (typically 1 kHz).
3. A test cable is connected between the analyzer source port and the test set input port. A test cable is
connected to the test set output port.
4. A power sensor is connected to the end of the test cable.
5. For a series of CW frequencies across the analyzer's full frequency range, the source output level is
adjusted to achieve the specified receiver compression power level (typically the receiver's maximum
input power level).
6. The power sensor is disconnected from the test cable and the cable is connected to the port to be
tested.
7. The analyzer steps through each CW frequency as the absolute log magnitude value (dBm) and the
relative phase for the receiver under test is read (P
8. The first test set output attenuator is set to 20 dB.
9. The magnitude and phase measurements using the receiver under test are read: (P
10. The second test set output attenuator is set to 20 dB.
11. The magnitude and phase measurements using the receiver under test are read: (P
12. The first test set output attenuator is set to 0 dB.
13. The magnitude and phase measurements using the receiver under test are read: (P
14. The compression for each point is calculated as (P
3-34
PNA Series Microwave Network Analyzers
).
a
–P ) – (P –P ).
a b d c
N5224A and N5225A
).
b
).
c
).
d
Service Guide N5225-90001