This paper presents the design of a wide-tuning range, low phase-noise, quadrature LC-tank VCO in a standard 90-nm CMOS technology. The LC oscillator has a quadrature core with complementary cross-coupled MOS devices. The oscillation frequency can be tuned from 28GHz -42GHz, with a control voltage between 0.3 and 1.0 V. The quadrature VCO core draws a maximum of 6mA current from a 1.2V supply. The circuit occupies a layout area of only 100 x 250 µm 2 .