Design and Application of Virtual Inductance of Square-Shaped Defected Ground Structure in 0.18- $\mu \text{m}$ CMOS Technology

This paper investigates a possibility of application of a virtual inductor realized by an integrated defected ground structure (DGS) to design a front-end circuit in CMOS technology. Two types of DGS are analyzed and found that the inductance realized by a square-shaped DGS achieves smaller size and higher quality factor than an H-shaped DGS. Then, a 15-GHz low phase noise voltage-controlled oscillator (VCO) employing the proposed square-shaped DGS in 0.18-
$\mu \text{m}$
1P6M CMOS technology is designed. The fabricated VCO operates from 15.2 to 16.12 GHz and consumes 5-mW power. The measured phase noise is −132.08 dBc/Hz at 10-MHz offset frequency, and this results in the figure of merit (FoM) and FoM taking account of the area to be 189.1 and 199.9 dB, respectively.