Left-handed tri-section stepped-impedance resonator

In this paper, a novel microstrip Tri-section Stepped Impedance Resonator (TSIR) based on Composite Right/Left-Handed (CRLH) transmission line is presented to resonate at the fundamental frequency of 2.5 GHz for Wireless Local Area Network (WLAN) applications. The left-handed TSIR is utilised to relocate the multiple resonance frequencies while maintaining the fundamental frequency the same. Supported by theory and full-wave simulations, a comparison is made between this design and its conventional counterpart. The CRLH SIR design presented in this paper is not only 30% smaller in length than its conventional counterpart, but also benefits from a much better performance in terms of relocating multiple resonance frequencies; very much applicable to microwave bandpass filters.