Study on Resonant Microstrip Line Coupled to a Double-gap Split Ring Resonator for Various Microwave Filter Applications

A resonant microstrip line (MTL) based on a square-shaped double-gap split ring resonator (DSRR), with parallel split-gaps placed symmetrically on opposite sides, is studied for various types of microwave filter applications. At first, a mode-splitting characteristic is observed for a DSRR loaded resonant microstrip line. Then, variation of rejection depth with resonance frequency are examined with variation of side-length and split-gap as well as with coupling distances between MTL and SRR, keeping other parameters constant. Depending on parameters of this coupled system, characteristics pertaining to a notch filter, a band-stop filter and also, a dual-band stop filter are obtained for microwave device applications.