Improve Two-Tone, Third-Order Intermodulation Testing

The two most common errors in the measuring process are (1) failure to provide adequate isolation between the two input signal generators and proper impedance matching, and (2) insufficient filtering of the two input test signals. Without adequate isolation and matching, interaction between the test generators and the device-under-test may produce significant errors (as high as 20 dB). Without sufficient filtering, the generator harmonics will contribute to the distortion displayed on the spectrum analyzer and device performance thus will not be properly evaluated.