ABSTRACTThis article presents a new quadrature voltage‐controlled oscillator (QVCO). The LC‐tank QVCO consists of two first‐harmonic injection‐locked oscillators (ILOs). The outputs of one ILO are injected to the common nodes of capacitors on the other ILO and vice versa so as to force the two ILOs operate in quadrature. At the supply voltage of 1.1 V, the total power consumption is 5.94 mW. The free‐running frequency tuning range is 11.5%, tunable from 6.56 to 7.36 GHz as the tuning voltage is varied from 0.0 to 2 V. The QVCO has been implemented with the TSMC 0.18‐μm CMOS technology and the die area is 0.504 × 0.803 mm2. The measured phase noise at 1‐MHz offset is −123.01 dBc/Hz at the oscillation frequency of 7.34 GHz and the figure of merit of the proposed QVCO is about −192.5 dBc/Hz. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:2528–2531, 2013