A compact transmission line with dual‐band filter characteristics using a CRLH metamaterial

Abstract

ABSTRACTIn this article, a size‐reduced dual band‐pass transmission line (TL) with a composite right/left handed (CRLH) shunt‐stub is presented. It uses a T‐shaped quarter‐wavelength TL, which shows dual band‐pass characteristics, when the electrical length is +nλ/4 or −nλ/4, where n is odd integer. These wavelengths can be achieved at arbitrary frequencies by the CRLH‐TL with the property of a nonlinear β versus ω. The phase delay at the two operating frequencies can be adjusted by designing the series TL part, identical to the case of a conventional TL. The performance of this TL is demonstrated in both simulations and measurements, which show good agreement, exhibiting insertion losses of 0.32 and 0.98 dB at the two operating frequencies, respectively. Also, the phase response difference was determined to be 180° at these frequencies. The size of the proposed TL is 16 × 19 mm2. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2150–2153, 2014