A Linear Network Description of Electromagnetic Coupling in MRI Coils Using Dependent Voltage Sources

作者：Mirsad Mahmutović, M Shrestha, Jason Stockmann, Harald E. Möller, Boris Keil · 发表于：IEEE Journal of Electromagnetics RF and Microwaves in Medicine and Biology · 年份：2026 · DOI：10.1109/jerm.2026.3702918 · 研究领域：Advanced MRI Techniques and Applications、Functional Brain Connectivity Studies、NMR spectroscopy and applications

Radiofrequency (RF) coil development for magnetic resonance imaging (MRI) relies on iterative bench-top adjustments in which tuning, impedance matching, preamplifier decoupling, and active detuning are optimized through repeated refinement of circuit component values and network analyzer measurements. Existing analytical descriptions used to guide this process commonly employ equivalent-circuit transformations that merge magnetic interactions into shared impedance elements, obscuring the contribution of individual components and not naturally accommodating the double-probe transmission measurement used during coil characterization. This work presents an alternative formulation in which electromagnetic coupling is introduced exclusively through dependent voltage sources, allowing each loop, whether belonging to the coil or to the double-probe, to retain its own circuit identity within a unified linear network. The scattering parameters observed on the bench follow directly from the mesh-current solution while maintaining a transparent one-to-one correspondence between lumped elements and their physical counterparts. Experimental validation on a receive coil at 123.25 MHz demonstrates close agreement between predicted and measured scattering parameters across all relevant operating states, with accurate reproduction of resonance frequencies, bandwidths, and spectral characteristics. The resulting network description provides a practical and extensible basis for predictive compo...