Non-Harmonic Spurious

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

To eliminate the effect of the spectrum analyzer’s frequency response error, a ”r;flatness calibration” is performed at each measured test point. To do this, the DUT is set to the non-harmonic frequency at the specified power level, and then spectrum analyzer performs a marker-peak-search and a marker-peak-to-reference-level. The DUT is then set to the fundamental frequency at the same power level and the spectrum analyzer performs a marker-delta measurement to determine the difference between the fundamental and non-harmonic components. This ”r;calibration” is done for every test point up to the frequency limit of the DUT.

Required Test Equipment

Instrument	Critical Specifications for This Test	Recommended Model¹
Spectrum Analyzer	None	E444xA² Opt 1DS, 123³
10 dB Attenuator	None	8491B Opt 010

Refer to the main equipment list for alternate models.
Depending on your frequency range needs, choose either an E4440A, E4443A, E4445A, E4446A, or E4448A. (E4447A is for Power Level Accuracy adjustment only.)
Options 1DS and 123 are for ESGs > 3 GHz.

Connections and Setup Procedures

All test equipment requires a 30 minute warm-up period to ensure accurate performance.
In the following test setup, direct cable and adapter connections are designated as solid lines. Changeable cable and adapter 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.