Compact Dual-Mode Microstrip Quasi-Meander Loop Resonator for Filter Applications

A compact microstrip dual-mode resonator is proposed for asymmetric response filter applications. The proposed microstrip dual-mode resonator that has form of a quasi-meander shaped loop resonator is investigated using a full-wave electromagnetic simulator. It is found that the degenerate modes, i.e., the odd and even modes, within this dual-mode resonator exhibit behavior similar to that of conventional dual-mode loop resonator. It is shown that there are two transmission zeros. The one of them is inherently associated with the dual-mode resonator structure and the other one is inherently associated with the odd mode. Two asymmetrical response filters exhibiting two transmission zeros in the upper stopband, and two transmission zeros in the lower and upper stopbands are realized utilizing dual-mode quasi-meander loop resonator.