A Novel Design Methodology for MSSW Transmission Lines Without Iteratively Solving Maxwell-Landau-Lifshitz-Gilbert Equation

Magnetostatic surface wave (MSSW) has unique features of unidirectional propagation, slow group velocity, and magnetic tunability, leading to wide applications in microwave devices and components like magnetostatic surface wave transmission lines (MSSW-TLs) for analog signal processing. Due to the strong interaction between MSSW and RF signals, solving the coupled Maxwell-Landau-Lifshitz-Gilbert (Maxwell-LLG) equations is necessary in modeling MSSW devices, which is however resource-intensive and time-consuming. To avoid solving the coupled equations, in this work, a novel design methodology based on the analogy between magnetic biasing and amplification is proposed for MSSW-TLs. The performance of a biased MSSW-TL can thus be easily predicted by its unbiased performance (Maxwell's equation only) with an amplification factor, leading to a rapid optimization process that is accelerated by ~100. An yttrium iron garnet (YIG)-based MSSW-TL prototype is successfully designed using the proposed method. The experimental data proves the effectiveness of the proposed design methodology. © 2024 IEEE.