Switchable bandpass filter using CRLH cells based on a new kind of admittance inverter

Abstract

Switchable bandpass filter using CRLH cells based on a new kind of admittance inverter samaneh keshavarzi and zahra atlasbafIn this paper, a new kind of admittance inverter and design of a switchable microstrip bandpass filter using composite right/ left-handed (CRLH) cells has been presented. The proposed filter has two states (or passbands). One of the two passbands, is accessible at each time by on/off state of three PIN diodes. This filter is a three-pole, coupled resonator filter, composed of short-circuited shunt resonators. These resonators are coupled using admittance inverters. With regard to the characteristics of the equivalent circuit of CRLH cells, a new structure of admittance inverter (J-inverter) has been introduced. This novel J-inverter has PI-section equivalent circuit and it consists of both inductive and capacitive elements. In our work, the proposed J-inverter was mathematically studied and the switchable filter was simulated and implemented. The results of simulations for the first and second state of the filter, which are frequency bands of (D1 ¼ 0.11 and f1 ¼ 1.26 GHz) and (D2 ¼ 0.12 and f2 ¼ 1.5 GHz), are verified by measurements.

Compact Dual-Wideband Bandpass Filter Using CSRR Based Extended Right/Left-Handed Transmission Line

“…Recently, metamaterial based composite right/left-handed (CRLH) transmission line has introduced a new method for designing and miniaturizing multiband microwave devices due to its unique phase response [6]. Moreover, CRLH transmission line is utilized in designing a single wideband bandpass filter [7][8][9][10]. For instance, in [11] and [12] an ultra-wideband bandpass filter is achieved by adopting the concept of balanced CRLH-TL to obtain a single band pass filter without any gap between right-and left-handed passbands.…”