Miniaturized Dual Bandstop Filter using CRLH Transmission Line

Abstract

Design of a dual wide bandstop filter is proposed based on Composite Right and Left-Handed Transmission-line (CRLH-TL) . Two stop bands with center frequencies of 8.3 GHz and 12.9 GHz are achieved with fractional bandwidths 57.8% and 32.5% respectively. Spiral interdigital capacitors and stub inductors are employed to designed filter. The proposed bandstop filter provides low passband insertion loss, better attenuation in stopbands, and low cost. The total filter size is about 7.8mm×15.1mm which is very compact compared to other metamaterial and conventional microstrip filters. Filter is also fabricated and measured to demonstrate the performance matched with simulation results.