A novel capacitive loaded structure for miniaturized resonators

Abstract

Miniaturized resonators are designed with variable capacitive loading capability by utilizing both sides of the substrates with Printed Circuit Board technology. The proposed design integrates a spiral‐shaped sub‐wavelength inductive element with a parallel plate resonant structure of three variations to achieve notch depths of 37, 39, and 48 dB at 94, 138, and 116 MHz respectively within an area of 6.1 by 9.65 cm2 with reduced insertion losses and narrowed bandwidths. The ratio between the largest dimensions of structure to their guided wavelengths at resonance are all <0.05, demonstrating exceptional compactness of the design without sacrificing the performance of band‐rejection behavior. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:2554–2557, 2016