A Compact Meander Line-Resonator Hybrid Structure for Wideband Common-Mode Suppression

In this paper, a novel compact and wideband common-mode suppression structure is proposed, which is composed of a meander line and several quarter wavelength resonators. A simple and accurate transmission line model is employed to describe the stopband behavior of the proposed structure. The resonance frequencies and harmonics of quarter wavelength resonators are employed to form stopbands of the common mode. Those stopbands together with the stopband of the meander line are connected in series, which are useful to expand the common-mode suppression bandwidth. Meanwhile, compensation strips are proposed to reduce the insertion loss of the differential mode. A reduction of 15 dB of common-mode propagation above 0.8 GHz is obtained by using the proposed hybrid structure. The measurement results of printed circuit boards, which are designed and fabricated on the simulation model, show good correlation with the simulation results.