Resonant coupling of coplanar waveguides with ferromagnetic tubes

TL;DR

This paper investigates how ferromagnetic Co90Ta5Zr5 tubes influence the resonant coupling of coplanar waveguides, revealing multiple surface modes and demonstrating the importance of topology and dimensions over shape.

Contribution

It introduces a novel experimental setup with ferromagnetic tubes to study resonant coupling and correlates the observed modes with micromagnetic simulations, highlighting topology's role.

Findings

Identification of ferromagnetic resonance and surface modes

Good agreement between experiments and simulations

Modes depend mainly on topology and dimensions

Abstract

Resonant coupling of coplanar waveguides is explored by wrapping proximate shorted ends of the waveguides with micron size ferromagnetic Co90Ta5Zr5 tubes. Ferromagnetic resonance and up to 7 outer surface modes are identified. Experimental results for these contorted rectangular tubes are in good agreement with micromagnetic simulations and model calculations of magnetostatic modes for an elliptical ferromagnetic tube. These results indicate that the modes are largely determined by tube topology and dimensions but less so by the detailed shape.