Establishing the minimum reverse bias for a p-i-n diode in a high-power switch

An important circuit design parameter in a high-power p-i-n diode application is the selection of an appropriate applied DC reverse bias voltage. Until now, this important circuit parameter has been chosen either conservatively, using the magnitude of the peak RF voltage, or by empirical trials to determine a possible lower value. The reverse bias requirement for a p-i-n diode operating in a high-power RF and microwave environment is explored. It is demonstrated that the minimum reverse bias voltage is equivalent to the p-i-n diode´s self-generated DC voltage under similar RF conditions. A concise expression for this self-generated voltage is developed and experimentally verified and should assist the design engineer in more accurately selecting an appropriate minimum value for the applied reverse bias voltage setting