Energy-Selective-Surface Limiter With Expanded Power-Handling Range Based on a Coupling Loop

Energy-selective surfaces (ESSs), which function as spatial electromagnetic limiters, face a fundamental challenge in balancing response threshold and breakdown power. Current ESS designs primarily emphasize transmission loss and shielding effectiveness (SE) while neglecting the critical tradeoff between these two performance metrics. To address this limitation, a 3-D unit cell with an embedded coupling loop has been developed, which can enable the conversion of spatial waves into guided waves and facilitating the redistribution of induced voltage. The integration of complementary diodes (high-sensitivity/high-breakdown diode pairs) allows for adaptive power-path switching, ensuring that low-power signals are directed to high-sensitivity diodes while high-power signals are redirected to high-breakdown diodes. Prototypes of the ESS have been fabricated and measured, and the results demonstrate that this design effectively resolves the inherent performance tradeoff. This ESS can play a significant role in high-power microwave (HPM) protection for sensitive RF equipment, either as a plug-in for waveguides or as a front-end solution for antennas.