A low phase noise quadrature phase oscillator with frequency pulling suppression technique

A high performance X-band quadrature phase voltage controlled oscillator for direct-conversion transceivers in 0.18-μm CMOS is demonstrated. By using the novel 8-shaped transformer topology, the proposed quadrature phase VCO can be operated at reduced dc power consumption while maintaining low phase noise with suppressed EMC (Electro-Magnetic Compatibility) issues Consuming a dc bias current of 5.45 mA with the supply voltage of 1.8V, the QVCO has a frequency tuning range of 570 MHz, a phase noise of −121.12 dBc/Hz at 1MHz offset frequency away from the 10.5 GHz carrier frequency, and an FoM up to 191.9 dBc/Hz.