Harmonic Spurious

Harmonics are signal impurities that occur at integer multiples of a fundamental signal. For example, the 2nd harmonic frequency is two times the fundamental frequency. In this test, a spectrum analyzer measures the power of a harmonic component relative to the power of the fundamental frequency component.

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.

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.