Non-linear modelling of microwave PIN diode switches for harmonic and intermodulation distortion simulation

The paper presents for the first time a practical and relatively simple non-linear modeling solution for /spl mu/-wave PIN diodes for use in harmonic balance (HB) circuit simulators. It enables very good prediction performance of the very important harmonic and intermodulation characteristics of these devices when used in typical /spl mu/-wave switching applications. Accurate harmonic distortion measurements have been performed on a number of commercial surface mount PIN diodes, over a wide range of relevant bias conditions and RF power levels. Parasitic elements are first extracted from microwave S-parameter data. Separate non-linear circuit models are then used for the ON and OFF states of the PIN diodes, and these are directly optimized on the measured harmonic distortion data using a dedicated modeling platform developed within a commercial modeling software tool. The new models have been implemented and tested in a popular harmonic balance circuit simulator with very good results. The modeling solution described here can be also applied to other active devices for similar large-signal modeling problems.