Microwave FET amplifier stability analysis using Geometrically-Derived Stability Factors

In this paper, the concept of stability in the design of microwave amplifier is re-visited. With the help of EDA tools, the determination of the microwave amplifier stability is simplified through the derivation of Geometrically-Derive Source (μ
_source
) and Load (μ
_load
) Stability Factors along with the Rollet Stability Factor (K-Factor). The effects of stabilization elements and layout parasitics i.e. ground inductance towards the amplifier's stability and were discussed. The techniques are then demonstrated with the ATF-50189 E-pHEMT microwave amplifier typical parameters.