Evaluation of 4H-SiC varactor diodes for microwave applications

The suitability of SiC p-n junction and Schottky varactor diodes for high frequency applications is demonstrated. It is shown that such devices are capable of operating at high biases (over 130 V)-offering greater power density, impedance and operating temperature compared to conventional GaAs or Si varactors. The limitations induced by relatively high contact resistivities are evaluated in terms of applications at 10 GHz.