Microwave hybrid resonance with an electromagnetic metasurface

Hybrid resonances were discovered in acoustics a few years ago. Here we demonstrate through full waveform simulations the realization of microwave hybrid resonance by using a simple H-fractal metallic metasurface, with unit cell’s lateral dimension much subwavelength in size. With an extremely thin back cavity, the resonances of the metallic structure at different frequencies can be hybridized to generate a new mode near the anti-resonance frequency. The oscillator strength and dissipation power of the hybrid resonance can be easily tuned, with total absorption occurring when the surface impedance matches that of vacuum. Similar to the acoustic case, the local fields are found to be much larger than the incident wave amplitude while the surface averaged fields are comparable to the incident fields. The total thickness of the surface is less than the peak absorption wavelength by two orders of magnitude. And we also found this mircowave hybrid resonance by using the metallic metasurface and its complementary structure, which is hard to achieve in acoustics.