Design Technique for High-Efficiency Frequency Doublers Based on the Manley and Rowe Energy Relations

This paper describes a design technique for high-efficiency microwave frequency doublers using a varactor diode. In this technique design parameters that can be measured in microwave circuits are derived from the Manley and Rowe energy relations in nonlinear reactances. These design parameters are: the characteristic impedances of the transmission lines of the microwave structure, the input and output powers of the frequency doubler, and the distances between the varactor diode and the filters that reject the fundamental frequency and the second harmonic.