1. Introduction
2. Analysis and Modeling of Ring Resonators
3. Modes, Perturbations, and Coupling Methods of Ring Resonators
4. Electronically Tunable Ring Resonators
5. Electronically Switchable Ring Resonators
6. Measurement Applications Using Ring Resonators
7. Filter Applications 153
8. Ring Couplers
9. Ring Magic-T Circuits
10. Waveguide Ring Resonators and Filters
11. Ring Antennas and Frequency-Selective Surfaces
12. Ring Mixers, Oscillators, and Other Applications