An Active Inductor Based Quadrature Voltage-Controlled Oscillator in $\mathbf{0.13}\mu\mathbf{m}$ CMOS

The design and measurement of a voltage controlled oscillator with quadrature outputs using a CMOS active inductor is presented. The coarse tuning of the quadrature VCO (QVCO) is accomplished through bias current tuning and varactors are added for fine tuning. The oscillator facilitates two working states. When supplied with 1.2 V supply voltage, the tuning range is 1–2 GHz and the phase noise (PN) varies from −71 dBc to −110 dBc at a 1 MHz offset from the carrier frequency. When the QVCO is supplied with 1 V supply voltage, the frequency tuning range is 0.7-1.5 GHz and the measured phase noise is from −71 dBc to −102 dBc at a 1 MHz offset. The output power varies less than 2 dB along all working conditions. The QVCO occupies an area less than 0.015 mm2. Except the output buffer, it consumes 2.5-2.7 mA from 1 V supply and 6.4-7 mA from 1.2 V supply.