Q-Factor Improvement of FR-4 Embeeded RF Inductors using Meshed Ground Plane

In this paper, FR-4 embedded circular spiral inductors with meshed ground planes are newly designed and fabricated, and characterized in order to improve their quality factors. The meshed ground plane is applied to reduce the induced loop current loss of the inductor. Interdependency of size, spacing, and location of the meshed ground plane on their performance characteristics are also investigated. The embedded RF inductors with the meshed ground plane (MGP) at 8th layer has inductance of 10.3nH at 800MHz, maximum quality factor of 74.1 at 1.1GHz, and SRF of 3.76GHz, respectively. The maximum quality factor of the inductor with a MGP at 8th layer was improved by approximately 32% in comparison to that of the inductor with the solid ground plane (SGP). These embedded high-Q inductors into FR-4 packaging substrate might be useful for advanced RF/wireless systems since they have excellent performance characteristics, small size, and light volume.