Frequency-doubling circuit

摘要

A frequency doubling circuit for doubling the fundamental frequency of a signal wave, comprising a pair of full-wave rectifier circuits which produce output signals which are subtracted to derive the second harmonic of the fundamental frequency. The direct current component and unwanted harmonics produced by the rectifier circuits are suppressed by capacitive loading which establishes a phase-quadrature relationship between the fundamental signal waves applied to both rectifier circuits, and adaptively maintaining the amplitudes of the fundamental frequency signals produced thereby equal by means of a negative feedback gain control loop.