Low phase noise voltage controlled oscillator

Abstract From the Canadian patent

A varactor diode tuned voltage controlled oscillator which simultaneously optimizes several techniques to minimize AM to FM conversion in the LC resonant circuit to provide an RF signal having minimum phase noise is described. A high gain current limiting RF amplifier is coupled to a high Q, high capacitance low impedance LC resonant circuit by an impedance transformation network to provide a high tank circulating power having minimum RF voltage fluctuations. The RF voltage across the varactor tuning diodes is further reduced by connecting two varactor diodes in series, back-to-back, or by connecting a fixed capacitance in series with the parallel connected varactor diodes.