Composite right/left‐handed‐coupled line bandpass filter using the first negative resonant mode

Abstract

In this letter, a high‐order composite right/left‐handed (CRLH)‐coupled line bandpass filter using the first negative resonant mode is presented. The unit‐cell structure of a half wavelength resonator is composed of an interdigital capacitor for a series capacitance and a shorted stub for a shunt inductance, respectively. The design equations are derived from those of a conventional coupled line filter. The even‐mode and odd‐mode impedances of a CRLH‐coupled line section are obtained using full wave simulation to complete the design equations. An insertion loss of a CRLH filter is suppressed from 2.1 to 1.1 dB by adding via hole in the end of resonators. The size of a CRLH filter is reduced by 53%, compared with that of conventional coupled line bandpass filter. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:943–947, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25856

Dual-band bandpass filter based on mixed electric and magnetic coupling of the hybrid quasi-lumped resonator

“…Stopband extension has also been improved by some researchers (Kuo, Fan, & Tang, 2012); though a deep wide stopband is realised, the frequency selectivity of these filters are not good. The properties of composite right-/left-handed transmission line (CRLH-TL) have been studied and applied to various microwave components (Bonache et al, 2004;Kim, Park, & Lee, 2010;Nguyen & Caloz, 2007;Sungtek, Geonho, & Jaume, 2010;Yang, Chi, & Itoh, 2011;Yang, Tamura, & Itoh, 2010). But few works have explained the electric and magnetic couplings of the CRLH-TL unit.…”

Dual band antenna designing with composite right/left handed

“…These parameters include series inductance, shunt capacitance, series capacitance and shunt inductance. At the fundamental mode of the CRLH‐TL, with decreasing frequency, the propagation constant increases so the resonance length λg/2 of antenna decreases and helps to design a compact antenna . These new elements provide left handed (LH) propagation and support backward wave idea.…”

Novel wide‐stopband bandpass filter with good frequency selectivity based on composite right/left handed transmission line

“…It combines the traditional transmission‐line theory with the novel structure and characteristics of the artificial material. Various microwave components have been proposed and used for practical applications based on such composite right/left‐handed transmission line (CRLH‐TL) approach [8–19]. All these applications based on the CRLH‐TL have demonstrated several unique features that cannot be realized by conventional right‐handed (RH) transmission lines.…”

“…The bandpass filter (BPF) is one of the key passive components in many microwave subsystems and has been widely studied [11–13, 15, 17, 18, 20–24]. With the development of microwave and RF technology, modern wireless systems require compact bandpass filters with excellent performance.…”

“…Meanwhile, the unique characteristics of negative‐order resonance and zero‐order resonance provide a new approach for filter design [5, 6, 17, 18]. Recently, many bandpass filters based on CRLH‐TL have been proposed [11–13, 15, 17, 18]. The method for synthesizing such kind of filters have been developed in [14, 15], and most of them have a very compact size and wide stopband.…”