A Compact PCB-Based Strong-Coupling Resonator for Oscillation Suppression of SiC MOSFETs

The high-speed switching of silicon carbide (SiC) power devices is often accompanied by voltage/current overshoot and high-frequency oscillation caused by circuit parasitics. Conventional solutions, such as RC snubber circuits or active gate drivers, often come at the cost of increased switching losses or system complexity. Meanwhile, RLC resonators face a trade-off between compactness and performance owing to weak coupling and large volume. To address these limitations, this paper proposes a novel strongly coupled resonator topology based on parity-time (PT) symmetric theory. The main breakthrough is the achievement of a coupling coefficient exceeding 0.4 within a compact 9 cm³ volume, ensuring efficient energy transfer and oscillation suppression at the physical level. This paper first constructs an RLC damping circuit with a strong-coupling topology, then integrates coupled-mode theory with circuit equations to establish a system energy model for guiding parameter design. Experimental results demonstrate a 77.15% reduction in turn‑offVds, 77.78% in turn‑offId, and 64.82% in turn‑onIdoscillations, with no significant additional loss. Compared to traditional methods, the proposed design provides improved oscillation suppression with low additional loss and compact size, offering a practical solution for high-speed SiC converters.