Design of 60-GHz Virtual Inductance via H-Shaped Defected Ground Structure with Projections

Defected Ground Structure (DGS) is a key innovation in RF circuit design that aims in enhancing quality (Q) factor of virtual inductance at high frequencies. By introducing intentional disruptions in the ground plane of conventional microstrip lines, the electromagnetic field gets interrupted resulting with increase in its characteristic impedance. This elevates the Q-factor of exhibited virtual inductance. This work demonstrates an approach of realizing virtual inductance at 60 GHz in DGS-based microstrip line by introducing projections on H-shaped defects. The proposed design uses two-level substrate that mitigates the substrate loss. Results shows that the self-inductance of $\mathbf{7 9. 2 1} \mathbf{~ p H}$ is exhibited by the proposed structure with Q-factor of 66.93 at 60 GHz, surpassing conventional on-chip spiral inductors. In this work, various structures involving projections on the circumference of H-shaped DGS have been introduced. In addition, for the first time this work presents exhaustive analysis of geometrical variations of H-shaped DGS and determines the optimal range of dimensions suitable for 60 GHz applications.