Spiral inductors integrated in MCM-D using the design space concept

High quality integrated spiral inductors are essential components of integrated microwave applications such as passive filters. In order to be able to determine the specific inductor geometry that provides the highest possible quality factor for a given inductance value and frequency behaviour, the concept of inductor design spaces is introduced. These design spaces link inductor quality factors with inductance values and frequency ranges. Using a new theoretical inductor model that allows the prediction of the behaviour of any coplanar multi-turn circular spiral inductor on a thin film multilayer MCM-D structure, the design spaces may be explored for the geometries that produce the highest quality factors. The paper describes both the calculation of the inductor model and the use of the design space concept. Finally, the application of this concept for the design of passive filters is indicated.