Low-phase-noise LC-VCO using high-Q 8-shaped inductor

An integrated LC-VCO using an 8-shaped inductor for reduced EM radiation is presented. A low phase noise is measured at 1 MHz offset ranging from 134 to 128 dBc/Hz for carrier frequencies from 2.9 to 3.47 GHz, respectively. The coil is implemented with a double aluminium metal layer and presents a measured quality factor Q 20 at 3 GHz. The circuit is realised in a 40 GHz-f T 0.25 m BiCMOS technology. Power consumption is about 13.5 mW from a 1.8 V regulated supply voltage.