Computation of Two-Port Parameters in Magnonic Devices Through Circuit-Field Coupling

This paper presents a model for the computation of two-port parameters from the configuration of a typical Magnonic device involving two coplanar waveguides. A Permalloy thin film is saturated using an appropriate dc field. The first waveguide then performs the function of excitation of spin waves by superposition of an RF field. The second waveguide detects the excited wave vector in Damon-Eshbach mode at resonance frequency. The model is solved using the generalized mean residual method for a linearized approximation of the Landau-Lifshitz-Gilbert equation coupled with Maxwell equations. Complex impedance matrices from the two-port network are extracted for both uniformly saturated and non-uniform initial ground states. Findings report low absorption potential and shift in resonance frequency for highly non-uniform ground states. Validation of the model for uniformly saturated ground states is performed against experimental and semi-analytical findings, showing good agreement.