The undesired effects of electromagnetic coupling between passive elements in MIC and MMIC designs are examined. Measured data of several strongly coupled circuit topologies commonly encountered in MMIC design are compared to simulations using circuit theory programs employing discontinuity models as well as electromagnetic field simulation tools. The results of this comparison are used to derive a set of specifications for a simulation tool suitable for use in the design of MIC and MMIC circuits. Copyright © 1991 Wiley Periodicals, Inc., A Wiley Company