Stability Analysis of Millimeter-Wave Circuits. Application to DC-40GHz PHEMT amplifier and Ku-band HBT power amplifier

Specific CAD oriented methods have been developed [1] for linear and non-linear stability analysis. Both methods are applied to multi-transistor MMIC circuits. These approaches can be easily implemented on any CAD packages and enable linear and non-linear stability to be analysed with a localization of instability paths within an N-transistor circuit. Simulations and measurements of two MMIC circuits (DC-40GHz PHEMT amplifier for optical links and Ku-band HBT power amplifier) demonstrate the efficiency of the proposed methods during the MMIC design processs.