COMPACT HIGH-SELECTIVITY BANDPASS FILTER USING A NOVEL UNIFORM COUPLED-LINE DUAL-MODE RESONATOR

摘要

Based on a single and uniform coupled-line section, a novel and simple dual-mode resonator with a wide range of external quality factor is proposed. The even-and odd-mode (dual-mode) resonance frequencies are created from unequal effective dielectric constants of a single coupled line. The operating principle is explained, and simulated examples are illustrated. Finally, a microstrip narrowband (14%) dual-mode high-selectivity bandpass filter operating at 2.6 GHz with two transmission zeros (2.02 and 2.97 GHz) is designed, fabricated, and measured. The good agreement between the simulated and measured results verifies this proposed idea. (C) 2015 Wiley Periodicals, Inc.