[Paper Review] Programmable radio-frequency calculations in electromagnetic-wave domain

Shao Nan Chen, Zhan Ye Chen+10 more|arXiv (Cornell University)|Jan 12, 2026

Metamaterials and Metasurfaces Applications0 citations

TL;DR

The paper proposes a space-time-coding metasurface (STCM) to perform direct RF calculations in the electromagnetic space, enabling Fourier transform and convolution in the EM domain for RF signal processing.

ABSTRACT

Information metasurfaces have emerged as pivotal components in next-generation electronic systems, with significant progress in their applications to communication, radar, and sensing. However, the current researches are mainly focused on their physical structures and system functions, while radio-frequency (RF) signal processing and calculation remain constrained to digital-domain operations. This reliance on digital conversion inherently increases hardware complexity and power consumption. To address this challenge, we propose a programmable RF calculation system based on a space-time-coding metasurface (STCM), which can control the wave-matter interactions through space-time-coding (STC) strategies and achieve direct RF calculations in the electromagnetic (EM) space in a reprogrammable way. Particularly, the fundamental signal operations - Fourier transform and convolution - are implemented in the EM-wave domain successfully. We validate the RF calculation capabilities in radar scenarios, facilitating the accurate detection of target velocity and range. Theoretical analysis, numerical simulations, and experimental results collectively demonstrate that the STCM-based RF calculation system exhibits superior precision, enhanced operational efficiency, and notable cost-effectiveness, highlighting its significant potentials for the next-generation electronic system deployments.

Motivation & Objective

• Motivate reducing digital conversion to lower hardware complexity and power consumption in RF signal processing.
• Introduce a programmable RF calculation system based on a space-time-coding metasurface (STCM).
• Demonstrate direct RF computations, specifically Fourier transform and convolution, in the electromagnetic domain.
• Validate the approach through theory, simulations, and experimental results in radar scenarios.

Proposed method

• Develop a programmable STCM to control wave–matter interactions via space-time-coding strategies.
• Realize Fourier transform and convolution operations directly in the electromagnetic-wave domain.
• Provide theoretical analysis to support STCM-based RF calculations.
• Conduct numerical simulations to validate performance.
• Perform experiments to demonstrate RF calculation capabilities in radar settings.

Experimental results

Research questions

• RQ1 Can space-time-coding metasurfaces implement fundamental RF operations like Fourier transform and convolution directly in the EM domain?
• RQ2 What gains in precision, efficiency, and cost can be achieved by moving RF calculations from digital to EM space?
• RQ3 How does STCM-based RF calculation perform in practical radar scenarios for target velocity and range detection?
• RQ4 What are the theoretical and experimental validations that support STCM-based RF computations?

Key findings

• STCM enables direct RF Fourier transform and convolution in the EM-space.
• The approach shows high precision in RF calculations and improved operational efficiency.
• Experimental results corroborate numerical simulations and theory.
• The system demonstrates potential cost-effectiveness for next-generation electronic systems.