Frequency-Hopping Wave Engineering with Metasurfaces

TL;DR

This paper introduces metasurfaces capable of dynamically controlling wave scattering based on frequency and pulse width, enabling frequency hopping-like behavior to enhance wave engineering applications.

Contribution

The work presents a novel metasurface design that manipulates scattering profiles using transient circuits, allowing frequency hopping in wave scattering for the first time.

Findings

Demonstrated variable scattering profiles with coupled transient circuits

Achieved increased frequency channels using factorial function scaling

Enabled frequency hopping-like control in wave scattering

Abstract

Wave phenomena can be artificially engineered by scattering from metasurfaces, which aids in the design of radio-frequency and optical devices for wireless communication, sensing, imaging, wireless power transfer and bio/medical applications. Scattering responses vary with changing frequency; conversely, they remain unchanged at a constant frequency, which has been a long-standing limitation in the design of devices leveraging wave scattering phenomena. Here, we present metasurfaces that can scatter incident waves according to two variables - the frequency and pulse width - in multiple bands. Significantly, these scattering profiles are characterized by how the frequencies are used in different time windows due to transient circuits. In particular, with coupled transient circuits, we demonstrate variable scattering profiles in response to unique frequency sequences, which can markedly increase the available frequency channels in accordance with a factorial function. Our proposed concept, which is analogous to frequency hopping in wireless communication, advances wave engineering in electromagnetics and related fields.