Some properties of travelling-wave resonance

The paper gives a description of travelling-wave resonance in a waveguide ring fed through a directional coupler, and a resonance theory is developed which describes the behaviour of waves in the ring and the reflection and transmission in the feeder in the neighbourhood of resonance. The theory allows for equal propagation coefficients for the ring waves, or for a different propagation coefficient for one of the waves, and for a reflecting discontinuity in the ring. A method of investigating the ring resonance is described using a travelling probe, and experimental results are given for the case of equal ring-wave propagation coefficients, which substantiate the theory.