Simple analysis of the frequency modes for microstrip ring resonators of any general shape and correction of an error in the literature

Unlike the conventional magnetic-wall model, a simple transmission-line model unaffected by boundary conditions is used to calculate the frequency modes of ring resonators of any general shape such as annular, square, or meander. Moreover, it corrects an error in the literature concerning the frequency modes of the one-port ring resonator. Also, it can be used to describe the dual-mode behavior of the ring resonator, which the magnetic-wall model cannot address well, especially for a ring resonator with complicated boundary conditions. Experiments show good agreement with theory. © 2003 Wiley Periodicals, Inc. Microwave Opt Technol Lett 38: 209–213, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11017