Miniature multilayer spiral inductors for GaAs MMICs

A model approach is presented for reducing the area consumed by MMIC (monolithic microwave integrated circuit) spiral inductors by exploiting a multilayer MMIC process. These spiral inductors can be designed to have inductance values as high as 20 nH but occupy areas of less than 0.1 mm/sup 2/. A simple analysis is presented to estimate the prime inductance, and the results of geometric optimization using a two-level electromagnetic field analysis are shown. A practical equivalent circuit has been developed together with a set of design equations. A miniaturized amplifier has been produced to demonstrate the successful application of the component.<<ETX>>