Energy Selective Surface With Power-Dependent Transmission Coefficient for High-Power Microwave Protection in Waveguide

This paper presents an energy selective surface (ESS) for high-power microwave (HPM) protection in waveguide, which has a nonlinear transmission response and can adaptively react to the power intensity of an incident wave. A prototype of four unit cells loaded with p-i-n diodes is designed and fabricated in L -band. The nonlinear and adaptive transmission characteristics are demonstrated by the waveguide measurements both in the time domain and frequency domain. On condition of signal power below 35 dBm, the wave in the interested band can propagate through waveguide with a low insertion loss down to 1 dB; while on condition of signal power above 47 dBm, high power would render the ESS into a high-impedance surface, and the incident wave would be reflected and dissipated with a transmission coefficient of less than -10 dB, thereby providing the HPM protection ability. Furthermore, the subsequent simulations illustrate that the inserted ESS will not worsen the radiation patterns of the following horn antenna and the induced high-order modes in waveguide keep negligible values below -65 dB.