Abstract
We propose a microwave realization of a metasurface that can delay broadband pulses without distortion in reflection. In order to obtain large and broadband pulse delay, we harness the synergetic phase delay of five sharply-resonant meta-atoms. More specifically, three electric-LC and two split ring resonators, supporting electric and magnetic dipole resonances, respectively, are combined in a subwavelength unit cell. The resonances are spectrally interleaved and specifically designed to provide a spectrally-constant reflection amplitude and group delay according to the prescription in [ACS Photonics 5, 1101, 2018]. The designed metasurface is electrically ultrathin (λ0/19), since it relies on resonant phase delay exclusively, instead of phase accumulation via propagation. We show delay of 700-MHz Gaussian pulses centred at 11 GHz by 1.9 ns, corresponding to approximately 21 carrier cycles. Our results highlight the practical potential of metasurfaces for broadband dispersion control applications.
Microwave realization of multiresonant metasurfaces for achromatic pulse delay