Implementation of Multipath Transformer in CMOS Voltage-Controlled Oscillator CMOS VCO Using Multi-Path Transformer

Abstract

A complementary oscillator was implemented in the TSMC $\mathbf{0.18} \mu\mathbf{m}$ 1P6M CMOS process, and it uses spiral multipath transformer to increase the quality factor of passive transformer. The multi-path transformer consists of a 3-path inductor internal to a single-path inductor used as the secondary inductor. The oscillator uses the Accumulation-mode MOS varactors for frequency tuning. The VCO uses no dynamic bias to lower the power consumption in steady state and the core current and power consumption of the oscillator are 4.05 mA and 4.457 m W, respectively at the de drain-source bias of 1.1 V. The oscillator can generate differential signals in the frequency range of 3.3-3.62 GHz. The die area of the oscillator is $\mathbf{1.148}\times\mathbf{0.987 mm}^{\mathbf{2}}$ .