On the interaction of the MMIC and its packaging

The software package WATMIC-EMsim is used to simulate the interaction of an MMIC circuit and its packaging. The circuit used is the spiral transformer, and the packaging is the surrounding ground ring used to interface the transformer to its coplanar probes. It is found that the resonant frequencies of the transformer are affected greatly with the introduction of the ring but, with its introduction, only slightly by the width of the ring. It is pointed out that this interaction mimics a well-known phenomenon in electrostatic capacitance. The results show that in the field-theoretic analysis of an MIC/MMIC circuit the influence of the packaging must be considered