A 1.0 V differential VCO in 0.13 μm CMOS technology

A differential complementary LC voltage controlled oscillator (VCO) with high Q on-chip inductor is presented. The parallel resonator of the VCO consists of inversion-mode MOS (I-MOS) capacitors and an on-chip inductor. The resonator Q factor is mainly limited by the on-chip inductor. It is optimized by designing a single turn inductor that has a simulated Q factor of about 35 at 6 GHz. The proposed VCO is implemented in the SMIC 0.13 μm 1P8M MMRF CMOS process, and the chip area is 1.0 x 0.8 mm2. The free-running frequency is from 5.73 to 6.35 GHz. When oscillating at 6.35 GHz, the current consumption is 2.55 mA from a supply voltage of 1.0 V and the measured phase noise at 1 MHz offset is -120.14 dBc/Hz. The figure of merit of the proposed VCO is -192.13 dBc/Hz. (semiconductor integrated circuits)