Experimental study of magnetodynamic edge-guided waves on a microwave ferrite substrate

This paper describes a microwave experimental study of the phase coefficient of magnetodynamic waves guided along a circular convex edge of a conducting film on a perpendicularly-magnetised ferrimagnetic substrate. The experiment consists of measuring the microwave resonance frequencies of a 10 mm radius gold disc on a O.5mm thick polycrystalline YIG plate, and identifying the azimuthal mode numbers ´n´. The measured dispersion curves for the edge-guided waves are compared with the theoretical results of de Santis. The measured phase velocities are found to be significantly greater than the theoretical values. The discrepancy may be caused by the theoretical assumption of a perfect magnetic wall at the disc edge. The experimental study is relevant to the design of miniature edge-wave nonreciprocal components that are being realised with instantaneous bandwidths much greater than an octave, e.g., 5-15 GHz.