Design and implementation of a self-decoupled figure-eight wireless coil array for ultra-high-field MRI

Magnetic resonance imaging (MRI) plays an indispensable role in clinical diagnosis owing to its high-resolution and non-invasive capabilities for soft tissue imaging. To further improve the signal-to-noise ratio (SNR) and enhance imaging performance, wireless surface coils have emerged as a promising approach to increase system flexibility. However, in high-density coil arrays, inter-element coupling and tuning complexity remain major challenges, particularly in the absence of direct physical connections.In this study, we propose a wireless coil array based on a figure-eight geometry, which enables passive decoupling without requiring geometric overlap. Unlike conventional designs, this structure maintains stable decoupling performance across multiple orientations while enhancing sensitivity to deep tissue signals. Although capacitors are still employed for tuning and can reduce coupling effects between coils, the figure-eight current path minimizes reliance on discrete inductive elements, thereby achieving more stable and simplified tuning in compact configurations.The proposed design provides a practical and efficient solution for constructing wireless MRI surface coil arrays with improved decoupling and tuning stability, paving the way for scalable multi-channel applications in advanced imaging systems.