A-192.7-dBc/Hz FoM KU-Band VCO Using a DGS Resonator With a High-Band Transmission Pole in 0.18-μm CMOS Technology

This letter presents the improvement of the phase noise (PN) of a voltage-controlled oscillator (VCO) by using a defected ground structure (DGS) resonator with a high-band transmission pole. The proposed DGS resonator has two loops in a coplanar stripline topology. The outer loop is loaded by a series capacitance, which produces the high-band transmission pole. The overall combination has a parallel capacitor to generate the necessary parallel resonance for the VCO operation. This proposed DGS resonator has a sharper impedance and frequency response slope, which results in an improved quality factor. In return, utilization of this DGS resonator into a K_{U}$ -Bnd VCO reduces its PN. The prototyped VCO in 0.18- $\mu \text{m}$ CMOS oscilltes t 15.52 GHz nd shows PN of -111.27 nd -134.07 dBc/Hz t 1- nd 10-MHz offset, respectively, while consuming 3.3-mW power. The VCO hs frequency tuning rnge of 9.5, which results in figure of merit (FoM) of -192.7 dB.