Wideband filtering power divider based on D-CRLH resonator

Abstract

In this paper, a wideband filtering power divider (FPD) based on dual-composite left–right-handed (D-CRLH) resonator is proposed. The D-CRLH filter unit, featuring a parallel stepped impedance resonator (SIR), is used to replace the λ/4 transmission line of the Wilkinson power divider, which can make the FPD more compact. Due to the inherent characteristics of D-CRLH resonator, two transmission zeros can be generated on both sides of the passband, so the proposed power divider based on the D-CRLH resonator can achieve a quasi-elliptic filtering response. To further enhance anti-interference ability at low frequencies, a pair of open stubs is added to the output feedline to introduce an additional transmission zero on the low-frequency side of the power divider passband. Finally, isolation resistors are introduced on the input and output feedlines to improve the isolation between the output ports. For validation, a prototype with a center frequency of 3.6 GHz is fabricated and measured, with −10 dB fractional bandwidths (FBWs) of 58.3 %(2.55–4.65 GHz). The measurement results are basically consistent with the simulation results, and its isolation in the passband is all more than 13.8 dB.