Design of a Spatial Multimode Energy-Selective Antenna Integrating Electromagnetic Protection and Anti-Interference Capabilities

A spatial multi-mode energy selective antenna integrating electromagnetic (EM) protection and anti-interference capabilities for high-intensity radiation fields (HIRF) is proposed in this communication. 1-bit phase modulation of the element is implemented by embedding a feed phase network into the patch and actively controlling single pole double throw (SPDT) devices, which enables compact configuration and precise phase control. Additionally, an energy selective protective structure is created by etching cavities around the coaxial feed probe, allowing for joint energy and spatial domain manipulation. Furthermore, a reciprocal high-power injection testing method is introduced, significantly reducing the cost of conventional irradiation measurements. The measured results for different spatial modes show excellent agreement with full-wave simulations. Within the operational frequency band, the shielding effectiveness (SE) peaks at over 12 dB, the interference suppression capability (ISC) exceeds 10 dB, and the comprehensive protective capability (CPC) achieves over 22 dB.