Large-signal analysis of varactor harmonic generators without idlers

A large-signal analysis of varactor harmonic generators without idlers is given. The voltage across the varactor is expressed as a Fourier series in the harmonic charges, and, by expressing the input circuit as an impedance, and the output circuit as a voltage generator in series with an impedance, the relevant coefficients of the series are found. It is found expedient to express the circuit in this way in order to determine the coefficients without any approximation. The efficiency is then calculated as a function of input power; it is found that, for maximum efficiency, input and output resistances should be equal and an expression is given to determine their value. Finally, design curves are given for second-, third- and fourth-harmonic generators, from which optimum operating conditions can be found.