Dual composite right/left‐handed unit with improved spurious performance and its application in wide‐stopband bandpass filter

Abstract

A compact dual composite right/left‐handed (D‐CRLH) unit with improved spurious performance is presented in this study. The proposed D‐CRLH unit consists of an interdigital capacitance (IDC) and a microstrip section inductor (MSI). Compared with the traditional IDC, the proposed IDC is improved by connecting the ends of the alternate fingers through the metallic paths on the back of the substrate. Thus, the spurious resonance at low frequency is eliminated and the usable bandwidth of the IDC is extended. The meander slots are also exploited in each finger of the IDC to increase the series capacitance, which contributes to reducing the circuit size. Furthermore, the proposed D‐CRLH unit is applied in the wide stopband bandpass filter (BPF) design to demonstrate its practicability. The BPF is fabricated and measured for demonstration. The measured results are in good agreement with the simulated results.

A PITD algorithm for analyzing composite right‐/left‐handed transmission line

“…In recent years, the composite right-/left-handed (CRLH) transmission line (TL) has gained considerable attention and has been widely used in microwave devices design, [1][2][3][4][5][6][7] which is owning to the merit of low loss, broadband, simple structure, and so on. On the other hand, to analyze problems or design devices, numerical tools are usually required.…”