Power-amplifier optimization using tunable circuitry and stability analysis methods for the next generation radar.

In response to the increasingly congested and contested wireless spectrum, the next generation radar must be adaptive and reconfigurable. A reconfigurable power amplifier is a necessary component of the cognitive radar system. The reconfigurable power-amplifier must operate efficiently and stably while maintaining spectrum compliance. The research in this thesis presents state-of-the-art tuning algorithms for optimizing the load reflection coefficient presented to a transistor by novel tunable circuitry. The algorithms are implemented on systems using a varactor diode network and a high-power handling evanescent mode cavity tuner as the tunable load matching networks. In addition, stability considerations are explored. A new amplifier design tool, the frequency Smith Tube, is presented which allows for broadband stability analysis for small-signal inputs. A real-time stability analysis procedure based on the acceleration of transducer gain during optimization is also presented.