Prediction of power and efficiency of frequency doublers using varactors exhibiting a general nonlinearity

Expressions for the power conversion capability and the efficiency of frequency doublers using fully-driven varactor diodes are derived from a series resistance-elastance model of the diode. Available methods of determining power and efficiency of graded and abrupt junction diodes are shown to be special cases of the derived expressions. The power and efficiency expressions as functions of the diode exponent may be used to describe the performance of frequency doublers using diodes with a wide range of capacitance-voltage non-linearities. Superior doubler performance is indicated for a specific class of diodes.