LC oscillator design at 10-GHz using substrate capacitance with scalable varactor parameters extraction technique

Design of quadrature oscillator at 10-GHz is demonstrated, which involved development of direct parameter extraction technique of scalable varactor. The varactor is used in the tank circuit. The effects of the substrate parasitic of SiGe in quadrature LC oscillator design were also investigated. Exploiting the substrate effect and accurate device characterization, a quadrature oscillator with -106-dB phase noise at 1-MHz offset using 2.50-V single supply was measured. The core oscillator consumes only 1.6-mA each at 10-GHz.