Design of a new low-phase-noise millimetre-wave quadrature voltage-controlled oscillator

Abstract

ABSTRACTThis paper presents a new circuit topology of millimetre-wave quadrature voltage-controlled oscillator (QVCO) using an improved Colpitts oscillator without tail bias. By employing an extra capacitance between the drain and source terminations of the transistors and optimising circuit values, a low-power and low-phase-noise (PN) oscillator is designed. For generating the output signals with 90° phase difference, a self-injection coupling network between two identical cores is used. The proposed QVCO dissipates no extra dc power for coupling, since there is no dc-path to ground for the coupled transistors and no extra noise is added to circuit. The best figure-of-merit is −188.5, the power consumption is 14.98–15.45 mW, in a standard 180-nm CMOS technology, for 58.2 GHz center frequency from 59.3 to 59.6 GHz. The PN is −104.86 dBc/Hz at 1-MHz offset.