Inductive and capacitive coupling modes of an RF coil to an ultra-High Dielectric Constant (uHDC) disk resonator

We investigated capacitive and inductive couplings of an RF coil to an ultra-High Dielectric Constant (uHDC) disk resonator with a given resonance mode of similar frequency using simulation and experiments. Coupling of the RF coil and uHDC resonator can result in splitting the resonance into two modes: a parallel mode via inductive coupling and an anti-parallel mode via capacitive coupling. With the two resonators, the stronger and deeper penetration of the resultant B1 field is observed with parallel mode (in-phase) than anti-parallel mode (out-of-phase), which supports that the parallel mode is preferable for coupling uHDC resonators for MRI applications.