Ultra-Wideband Strong Field Protection Device Based on Metasurface

In order to protect the electronic equipment from high-power microwave (HPM), this article proposes an ultra-wideband strong field protection device, which is composed of a bandpass metasurface cascaded with an active metasurface. When the active metasurface is illuminated by low-power signals, its transmission passband overlaps with that of the bandpass metasurface. So working signals can pass through the protection device. However, when HPM is incident, the resonant frequency of the active metasurface moves to the stopband of bandpass metasurface. Therefore, both in-band and out-of-band HPM are reflected. The steady-state and transient-state characteristic of the device are analyzed. Results indicated that the insertion loss of the device is less than 1.5 dB over the range of 3.38-4.33 GHz (relative bandwidth reaches 24.6%). Also, it has the shielding effectiveness better than 13 dB for HPM in the range of 0-20 GHz.