Sensitivity Enhancement in Pole-Zero Identification Based Stability Analysis of Microwave Circuits

In this work the use of a dual Current-Voltage (I-V) probe is proposed in order to improve the sensitivity of pole-zero identification based stability analyses. The benefits of this approach are shown here by its application to a parametric oscillation in an X-band multi-stage MMIC power amplifier and to a bias oscillation in a medium power FET amplifier built in hybrid microstrip technology.