Doppler cloaks are spatiotemporally modulated metamaterial covers to be placed in front or wrapped around a moving object to restore locally the source illumination frequency, as if it were not in motion. Although the cloak effectively compensates such a frequency shift, the required thickness of the metamaterial is in the order of dozens of wavelengths of the incident signal for ensuring a complete energy transfer from the Doppler shifted to the original source frequency. In this contribution, we present a bi-dimensional version of the Doppler cloak, realized by a time-varying metasurface with proper time-dependent transmission coefficient. The temporal profile of the transmission coefficient is defined for achieving the same frequency mixing behavior of bulk Doppler cloaks. The operation is verified by a full-wave FDTD numerical simulation in case of normal incidence.
Ramaccia, D., Sounas, D.L., Alu, A., Toscano, A., Bilotti, F. (2018). Metasurface-based Doppler cloaks: Time-varying metasurface profile to achieve perfect frequency mixing. In 2018 12th International Congress on Artificial Materials for Novel Wave Phenomena, METAMATERIALS 2018 (pp.331-333). Institute of Electrical and Electronics Engineers Inc. [10.1109/MetaMaterials.2018.8534167].
Metasurface-based Doppler cloaks: Time-varying metasurface profile to achieve perfect frequency mixing
Ramaccia D.
Writing – Original Draft Preparation
;Alu A.Membro del Collaboration Group
;Toscano A.Supervision
;Bilotti F.Supervision
2018-01-01
Abstract
Doppler cloaks are spatiotemporally modulated metamaterial covers to be placed in front or wrapped around a moving object to restore locally the source illumination frequency, as if it were not in motion. Although the cloak effectively compensates such a frequency shift, the required thickness of the metamaterial is in the order of dozens of wavelengths of the incident signal for ensuring a complete energy transfer from the Doppler shifted to the original source frequency. In this contribution, we present a bi-dimensional version of the Doppler cloak, realized by a time-varying metasurface with proper time-dependent transmission coefficient. The temporal profile of the transmission coefficient is defined for achieving the same frequency mixing behavior of bulk Doppler cloaks. The operation is verified by a full-wave FDTD numerical simulation in case of normal incidence.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
