Abstract

This paper describes potential stability problems occurring in transistor stages with inductive source feedback. These problems occur at very high frequencies, where modelling of passive components is far from trivial. Due to the increase in maximum operating frequency of submicron pHEMT transistors, this problem is recently attracting attention. After comprehensively showing the problem, a simulation strategy is suggested for a timely recognition of the problem. The effectiveness is proven for an MMIC example. Index Terms — MMIC’s, LNA’s, pHEMT, integrated circuits, stability analysis.