Computer-aided design of microwave integrated circuits

This paper describes how an analysis/optimization program in current use may be adapted for the design of m.i.c.s. The optimization routine combines two different strategies to reduce the execution time and increase the accuracy of approach to the true minimum. The analysis routine incorporates an algorithm for junction parasitics, dispersion, conductor and dielectric loss in the microstrip lines. The effects of these parameters, together with design details, are given and optimized results presented for several amplifiers, including an X-band single stage version, employing GaAs Schottky-gate field-effect transistors. This amplifier achieves 7 dB ± 0.5 dB gain, with 2.5 : 1 input and output v.s.w.r., over the frequency range 8–11.6 GHz.