Coupling enhancement of composite-right/left-handed loop resonators for filter applications

An enhanced method for the coupling of Composite-Right/Left-Handed (CRLH) loop resonators for filter design is presented in this paper. The proposed coupling mechanisms take advantage of the natural distribution of the E- and H-fields on a CRLH loop resonator, while maintaining the advantages in miniaturization and harmonic resonance suppression of such structures. For demonstration of the concept, two filters operating in the GSM-850 band are designed, fabricated and tested experimentally. Good agreement between the simulated and measured results is obtained.