Patent ID: 6970048

Claim:
An apparatus including an inductive-capacitive (LC) based quadrature voltage controlled oscillator (VCO) with a deterministic quadrature signal phase relationship, comprising: first LC VCO circuitry including first differential VCO input terminals to receive a differential feedback signal having a signal wavelength and first differential VCO output terminals to convey a first differential VCO signal; first phase shift circuitry including first differential phase shift input terminals directly coupled to said first differential VCO output terminals to receive said first differential VCO signal and first differential phase shift output terminals to convey a differential intermediate signal having said signal wavelength, wherein said first differential VCO signal and said differential intermediate signal differ in phase by a first phase difference less than a quarter of said signal wavelength with a predetermined polarity; second LC VCO circuitry including second differential VCO input terminals directly coupled to said first differential phase shift output terminals to receive said differential intermediate signal and second differential VCO output terminals to convey a second differential VCO signal; and second phase shift circuitry including second differential phase shift input terminals directly coupled to said second differential VCO output terminals to receive said second differential VCO signal and second differential phase shift output terminals cross coupled to said first differential VCO input terminals to convey said differential feedback signal, wherein said second differential VCO signal and said differential feedback signal differ in phase by a second phase difference less than said quarter of said signal wavelength with said predetermined polarity, and said differential intermediate signal and said differential feedback signal have mutually quadrature signal phases with a quadrature phase difference having said predetermined polarity.