STRIPLINE DUAL-MODE RING RESONATORS AND THEIR APPLICATION TO MICROWAVE DEVICES

This paper describes the fundamental properties of two orthogonal reso nant modes within stripline ring resonators and their application to m icrowave devices. There are two principal methods for application of r ing resonators, the first is by using two-port devices and the second four-port devices. In the case of two-port configurations, dual-mode f ilters using coupling between two degenerate modes have been studied a s typical applications. In this paper, new methods for the coupling of two modes and their applications to practical devices are proposed, a nd then experimental results for proof of the new structures are prese nted. Four-port configurations, which make use of two resonant modes a s being independent or having no coupling between them, have a wider r ange of application to microwave devices. Microwave circuits such as t uned amplifiers and oscillators with novel structures are proposed, an d their excellent characteristics are demonstrated. The experimental r esults obtained in this study on two and four-port devices make it cle ar that dual-mode ring resonators have great potential for application to various microwave devices.