Nonharmonic Spurious

Nonharmonic spurious responses are unwanted signals that are not related to the fundamental output frequency of the UUT that are produced by the internal frequency synthesis of the UUT. This test utilizes a spectrum analyzer to measure the amplitude of these responses relative to the amplitude of a fundamental frequency.

The spectrum analyzer and the signal generator are both tuned to the harmonic frequency and a reference amplitude measurement is made. Then, the signal generator is tuned to the fundamental frequency with the power level unchanged. The spectrum analyzer measures the resulting harmonic response relative to the reference amplitude. For spurious signals close to the fundamental where phase noise dominates over thermal noise, an additional noise measurement is made to correctly determine the measurement uncertainty due to noise.

Required Test Equipment

Test Equipment	Recommended Models	Alternate Models
Spectrum Analyzer	N9030B Opt 5xx¹	N9030A Opt 5xx¹ E444xA²

Select any option of PXA spectrum analyzer (503, 508, 513, 526, 543, 544, 550) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test.
Select any model of PSA spectrum analyzer (E4440A, E4443A, E4445A, E4446A, E4447A, E4448A) that has a maximum frequency greater than or equal to the maximum frequency of the unit under test.

Connections and Setup Procedures

All test equipment requires a 30 minute warmup period to ensure accurate performance.
In the following test setup, cables are designated as solid lines and direct connections are designated as dashed lines.

Connect all test equipment as shown.
Connect GPIB cables to all GPIB-controlled test equipment.
While performing this test, follow all instructions on the controller display.

In Case of Difficulty

If this performance test fails, perform the following steps in order:

Check the equipment setup (see above). If the setup is incorrect, make the necessary corrections and rerun the performance test.
If this test fails with the equipment set up properly, refer to the troubleshooting section of the signal generator's service guide. If you do not have a printed copy of the service guide (Option OBW), one is available either on the CD-ROM that came with your signal generator shipment or on the Keysight Website.
If you cannot correct the problem using the troubleshooting procedures in the Service Guide, obtain service from Keysight Technologies. Refer to Contacting Keysight Technologies.