Keysight Technologies N5244/5B Service Manual page 74

Tests and Adjustments
Performance Tests
Function of the Test: To measure the relative power linearity of the analyzer's
receivers.
Specification Tested: Test Port Input–Dynamic Accuracy
Equipment Used:
— U3020AD01 dynamic accuracy test set
— Signal generator
— Power meter
— Power sensor
— Two test cables
Description of the Test:
1. The analyzer's test ports are tested separately at a specific CW frequency
and a reference power level of -20 dBm.
2. A test cable is connected between the analyzer's source port and the
dynamic accuracy test set's Source 1 In port. A test cable is connected
between the signal generator and the test set's Source 2 In port. A test
cable is connected to the test set's Receiver Out port, and the power
sensor is connected to the end of this cable.
The test set's output attenuator is set to 20 dB. With the signal generator
RF turned off, the PNA source power is adjusted until the power sensor
reads -20 dBm. The PNA source is then turned off, the signal generator RF
is turned on, and the signal generator power is adjusted until the power
sensor reads -20 dBm.
3. The power sensor is disconnected and the test cable is attached to the
analyzer port under test.
4. Both sources are turned on and the signal generator's frequency is set to 2
Hz above the analyzer's frequency. By combining these two signals
together, the resultant signal will be a perfect sine wave with a magnitude
which varies from -17 dBm to -23 dBm at a rate of 2 Hz.
5. The analyzer's receiver measurement is retrieved and compared with a
perfect sine wave. Any deviation is due to receiver non-linearity.
6. The test set's output attenuator is changed in 5 dB steps from 0 to 60 dB,
and this measurement is repeated.
7. With the 1 dB of overlap in each measurement, the data for each
attenuator setting can be stitched together to provide a complete receiver
linearity profile from +3 dBm to -63 dBm.
8. This test is repeated for each receiver.
If the Analyzer Fails this Test:
— If the analyzer fails this test, rerun the test.
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