Agilent Technologies E1401-90493 31. Spurious Responses: Agilent E4402B and E4403B

Chapter 2 263

Performance Verification Tests

31. Spurious Responses: Agilent E4402B and E4403B

31. Spurious Responses: Agilent E4402B and

This test is performed in two parts. Part 1 measures third order

intermodulation distortion; Part 2 measures second harmonic

distortion.

To test second harmonic distortion, a low pass filter is used to filter the

source output, ensuring that harmonics read by the analyzer are

internally generated and not coming from the source. To measure the

distortion products, the power at the mixer is set 25 dB higher than

specified.

For example, if the specification states that with −30 dBm at the input

mixer, the distortion products should be suppressed by >75 dBc, the

equivalent second harmonic intercept (SHI) is >45 dBm (−30 dBm

+ 75 dBc). Measuring with −15 dBm at the mixer and verifying the

distortion products suppressed by >60 dBc also ensures the SHI is

>45 dBm (−15 dBm + 60 dBc).

For third order intermodulation distortion, two signals are combined in

a directional bridge to provide isolation. These two signals are applied

to the analyzer input. The power level of the two signals is several dB

higher than specified, so the distortion products should be suppressed

by less than the amount specified. In this manner, the equivalent third

order intercept (TOI) is measured.

For example, if the specification states that with two −30 dBm signals

at the input mixer, the distortion products should be suppressed by

>82 dBc, which yields a third order intercept of >11 dBm (−30 dBm

+ (82 dBc/2)). Measuring with −20 dBm at the mixer and verifying the

distortion products are suppressed by >62 dBc, the equivalent TOI is

also >11 dBm (−20 dBm + (62 dBc/2)).

There are no related adjustment procedures for this performance test.

Equipment Required

Synthesized signal generator

Synthesized sweeper

Power meter, dual channel

RF power sensor

Power splitter

Directional bridge

300 MHz low pass filter

Cable, APC 3.5, 91-cm (2 required)

Cable, BNC, 120-cm

Adapter, Type-N (m) to APC 3.5 (f) (3 required)

Adapter, Type-N (m) to SMA (m)