A new and simple measurement approach for characterizing intermodulation distortion without using a spectrum analyzer

This paper presents a novel test setup for characterizing intermodulation distortion in advanced devices and circuits. The setup uses a network analyzer to measure power levels of the fundamental and IM3 products for a two-tone input. It is shown that if the power calibration is correctly performed, the intermodulation distortion terms from a power sweep give the correct value of the input-referred third-order intercept point (IIP3). MOSFETs in a commercially-available 0.13 µm SiGe BiCMOS technology were measured across bias to validate the measurement approach. The results were subsequently validated using harmonic balance simulations based on design-kit compact models.