Diamond Schottky P-I-N Diodes For High Power Rf Receiver Protectors

The electrical characteristics of diamond Schottky p-i-n diodes grown by plasma enhanced chemical vapor deposition have been measured from DC to 25 GHz and used to extract the small-signal parameters for a lumpedelement compact model. The model accurately reproduces the forward and reverse bias DC characteristics, the capacitance-voltage behavior, as well as the insertion and reflection loss. The high thermal conductivity of diamond makes the diodes ideally suited for high power radar receiver protector applications. We demonstrate that under forward bias a single diode can provide 14 dB of input power attenuation. For self-biased limiter applications, a two-stage circuit with back-to-back diodes has been simulated using the diode model to show > 20 dB of attenuation at an input power of 50 dBm.