A multiphase VCO using differential active inductors is designed and fabricated in an IBM 0.13um CMOS process. Using active inductors, the core VCO occupies 0.3x0.4 mm2, and the central frequency can vary from 6GHz to 11GHz, exhibiting a 58% tunable frequency ranges. Exploiting current reuse, the phase noise is measured to be less than -95dBc/Hz at 1MHz offset with the measured power consumption ranging from 12 to 31mW in 6-11GHz. A signal coupling technique with phase shifting is employed to generate eight phase signals. The achieved phase errors of this design are smaller than 3°. In addition, bias compensation is shown to reduce the frequency variation under 10% while the temperature varies from -55°C to 125°C.