CUSTOM DESIGN OF MONOLITHIC MICROWAVE INTEGRATED-CIRCUITS

Monolithic microwave integrated circuits (MMIC's) have been designed a t the Applied Physics Laboratory and fabricated at several gallium ars enide foundries since 1989. The design tools and methods for designing MMIC's have evolved to the present use of integrated computer-aided e ngineering software with programmable design components. Software elem ents that can be customized create multilayer mask descriptions of com ponents for transistors, resistors, capacitors, inductors, microstrip connections, and other structures to improve the quality and productiv ity of MMIC's designed at the Laboratory. The schematic, physical layo ut, and simulation models are integrated into a single software tool, eliminating much potential for error. Experience with various foundrie s and various MMIC design techniques have increased our ability to des ign at higher and higher frequencies with confidence in achieving firs t-time success. The design improvements have been accompanied by impro vements in measurement techniques for higher frequencies using microwa ve probe stations. This article summarizes MMIC designs at the Laborat ory over the past few years and the progress shown and lessons learned .