This letter presents a dumbbell-shaped defected ground resonator and its application in the design of differential filters. The operation principle of the dumbbell-shaped resonator (DSR) coupled to differential microstrip lines is studied through a circuit model analysis. The proposed circuit model is validated through the comparison with the electromagnetic simulation results. It is shown that the bandpass configuration of microstripline- coupled DSR can be used to design higher order bandpass filters. The design procedure is explained by developing a thirdorder filter prototype. The designed filter shows more than 57 dB common mode rejection within the differential passband.
@article{arxiv.1802.07406,
title = {Differential Bandpass Filters Based on Dumbbell-Shaped Defected Ground Resonators},
author = {Amir Ebrahimi. Thomas Baum and Kamran Ghorbani},
journal= {arXiv preprint arXiv:1802.07406},
year = {2018}
}