Programmable metasurface achieves beam scanning and multi-band radar cross-section reduction

Mar 26, 2026

A new programmable metasurface performs dynamic beamforming and radar cross-section reduction across five frequency bands in a design 87% thinner than conventional approaches.

(Nanowerk News) Researchers at Xidian University have developed a programmable metasurface that performs dynamic beamforming for communication while simultaneously reducing radar cross-section (RCS) across its operating frequency band and four additional radar bands. The device, just 0.065 wavelengths thick, uses an intrinsic “self-stealth” mechanism that requires no external absorbers or added structural layers. The work, led by Long Li and Yajie Mu, was published in the journal Research (“A Low-Profile Self-Stealth Programmable Metasurface with In-Band and Out-of-Band RCS Reduction”).

Key Findings

Programmable metasurfaces are two-dimensional arrays of subwavelength artificial elements that manipulate electromagnetic waves. Embedding tunable components such as PIN diodes allows these surfaces to be digitally reconfigured in real time for beamforming, information modulation, and other functions central to smart wireless environments and future 6G systems. Most prior research has concentrated on radiation performance — beam scanning and gain — with only limited attention to stealth capabilities. Where stealth has been addressed, it has typically been confined to the metasurface’s own operating band through phase cancellation techniques. Radar systems operating outside that band, for example in S-band or C-band, can still detect the platform. No existing design has combined communication performance with broadband radar stealth in a single compact device without relying on additional absorptive layers or radomes that add thickness and RF loss. The new design resolves this gap through a co-aperture architecture that embeds both communication and stealth functions into a single surface. PIN diodes provide 1-bit digital phase control of x-polarized signals at 5.2 GHz, enabling ±45° beam scanning in two dimensions. Simultaneously, y-polarized structures built into the same aperture suppress scattering, so that communication and stealth operate without mutual interference. Conceptual illustration of the proposed low-profile self-stealth programmable metasurface. The metasurface exhibits radiation and stealth characteristics in the in-band co-polarization. It also demonstrates stealth characteristics in the in-band cross-polarization and out-of-band full-polarization. (Image: Reproduced from DOI:10.34133/research.1017, CC BY) (click on image to enlarge) For out-of-band stealth, the metasurface uses cross-dumbbell and branched resonant structures distributed across its top and middle layers. These elements cover four frequency bands beyond the operating band. A checkerboard arrangement of unit cells produces phase cancellation of scattered waves across all four bands, eliminating reflected energy without absorptive materials. Five independent resonators allow precise tuning at two low frequencies (3.6 GHz and 4.16 GHz), the center frequency (5.2 GHz), and two high frequencies (6.55 GHz and 7.43 GHz), maintaining 180°±37° phase differences across 70% bandwidth. The total thickness is 0.065 wavelengths at 5.2 GHz, compared to 0.51 wavelengths for conventional approaches — an 87% reduction that makes the surface practical for flush mounting on curved aircraft and drone structures. A 12×12-element prototype was fabricated and measured, with experimental results closely matching electromagnetic simulations. In communication mode, the prototype demonstrated two-dimensional beam scanning to ±45° at 5.2 GHz with a peak realized gain of 17.23 dBi and an aperture efficiency of 18%. For stealth performance, RCS reduction exceeded −6 dB for both x-polarization (4.9–5.3 GHz) and y-polarization (5.0–5.38 GHz) within the operating band, while out-of-band reduction exceeded −10 dB across all four stopbands. By co-locating dynamic beamforming and broadband stealth on a single thin surface, the design eliminates the need to trade radiation performance against physical size or power consumption. The researchers describe the metasurface as an “intelligent skin” capable of transmitting and receiving signals while concealing its host platform from radar detection across a wide frequency range. Target applications include 6G integrated sensing and communication systems, stealth-platform communication, and intelligent electromagnetic camouflage.