Highly performed PCB embedded inductors using inverted-patterned ground structure

In this paper, PCB embedded circular-stacked spiral inductors with the inverted-patterned ground (IPG) plane were designed, fabricated, and characterized in order to reduce their sizes and improve their quality factors. IPG structure was applied to reduce the induced loop current loss of the inductor. Interdependency of the line width and space of IPG plane on their performance characteristics are also investigated. The embedded inductor with four turns (1^st layer - 2 turns and 2^nd layer - 2 turns stacked), the size of 1 × 1 mm², and IPG plane exhibited inductance of 9.68 nH, quality factor of 71.5 at 1.5 GHz, and self resonant frequency of 3.98 GHz, respectively. The quality factor of the inductor with IPG plane was improved by approximately 20 % in comparison to that of the inductor with the solid ground plane. Moreover, when spaces of IPG plane were double than line widths of inductors, their quality factors were highly optimized for the best RF performances. The PCB embedded high Q inductors with IPG plane might be useful for advanced RF/wireless systems since they have excellent performance characteristics, small size, and light volume.