Residual Noise Identification for PIM Measurement Systems using Variable Low-PIM Termination

In this letter, we describe the design for the variable low-PIM termination composed of the voltage-controlled IM-source, a fixed attenuator, and a linear attenuator.

The design method for evaluating PIM-level of the fixed attenuator is presented in order not to limit the variable range of entire termination.

It is possible to maintain low-PIM performance in spite of using active voltage-controlled IM-source, whose IM level is extremely high.

This termination is used for a dynamic residual noise identification for PIM measurement systems by observing the saturation value for voltage sweep.

The validity is confirmed by experiments in 2GHz band.