This performance verication test must be performed with the EMC analyzer set in the spectrum analyzer mode.
This test is performed in four parts. The rst two parts measure the second harmonic distortion; the last two parts measure the third order intermodulation distortion. Second harmonic distortion and third order intermodulation distortion is checked in both low band (50 kHz to 2.9 GHz) and high band (2.75 to 12.8 GHz).
To test second harmonic distortion, 50 MHz and 4.4 GHz low pass lters are used to lter the source output, ensuring that harmonics read by the analyzer are internally generated and not coming from the source. The distortion products are measured using the EMC analyzer marker functions.
For third order intermodulation distortion, two signals are combined in a directional coupler (for isolation) and are applied to the analyzer input. The power level of the two signals is 8 dB higher than specied, so the distortion products should be suppressed by 16 dB less than specied. In this manner, the equivalent Third Order Intercept (TOI) is measured.
With two 030 dBm signals at the input mixer and the distortion products suppressed by 70 dBc, the equivalent TOI is +5 dBm (030 dBm + 70 dBc/2). However, if two 022 dBm signals are present at the input mixer and the distortion products are suppressed by 54 dBc, the equivalent TOI is also +5 dBm (022 dBm + 54 dBc/2). Performing the test with a higher power level maintains the measurement integrity while reducing both test time and the dependency upon the source noise sideband performance.
Equipment Required
Synthesized sweeper (two required)
Measuring receiver (used as a power meter)
Power sensor, 50 MHz to 12.8 GHz
Power splitter
Low pass lter, 50 MHz
Low pass lter, 4.4 GHz
Directional coupler
Cable, APC 3.5, 91 cm (36 in) (two required)
Cable, BNC, 120 cm (48 in)
Adapter, Type N (m) to APC 3.5 (m)