Space-Time-Modulated Wideband Radiation-Type Programmable Metasurface for Low Sidelobe Beamforming

TL;DR

This paper introduces a space-time modulated wideband programmable metasurface that enables low-profile, low-sidelobe beamforming without external feeds, using harmonic analysis for adaptive beam control.

Contribution

It proposes a novel space-time modulated metasurface design that reduces profile and enhances beamforming capabilities compared to traditional metasurfaces.

Findings

Achieves significant profile reduction by integrating microwave-fed excitation.

Enables high-accuracy amplitude-phase weight control for low sidelobe beam-scanning.

Allows adaptive beamforming and interference nulling through harmonic analysis.

Abstract

Programmable metasurfaces promise a great potential to construct low-cost phased array systems due to the capability of elaborate modulation over electromagnetic (EM) waves. However, they are in either reflective or transmissive mode, and usually possess a relatively high profile as a result of the external feed source. Besides, it is difficult to conduct multibit phase shift in metasurfaces, when comparing with conventional phased arrays. Here, we propose a strategy of space-time modulated wideband radiation-type programmable metasurface for low side-lobe beamforming. The wideband programmable metasurface avoids the space-feed external source required by its traditional counterpart, thus achieving a significant reduction of profile through integration of a highefficiency microwave-fed excitation network and metasurface. Furthermore, through introducing space-time-modulated strategy, the high-accuracy amplitude-phase weight algorithm can also be synchronously carried out on the first harmonic component for low side-lobe beam-scanning. Most importantly, adaptive beamforming and generation of interference null can further be created after analyzing the harmonic component characteristics of received signals.