Advanced dielectric materials play a central role in modern radio-frequency (RF) systems, underpinning applications such as antennas, resonators, 5G and satellite communications, radar, medical imaging, and emerging IoT technologies. The electrical performance and reliability of these systems critically depend on accurate knowledge of the complex permittivity of the materials used, often across wide frequency ranges. As RF technologies move toward higher frequencies, tighter integration, and more demanding performance constraints, the need for reliable, flexible, and affordable dielectric characterization tools has become increasingly acute.
Despite this need, current RF characterization techniques remain largely inaccessible to many industrial users. Established methods—including resonant cavities, coaxial probes, and free-space techniques—are either highly accurate but expensive and narrowband, or broadband but challenging to implement in practice. Comprehensive characterization across different materials, geometries, and frequency bands typically requires multiple dedicated test fixtures and advanced RF expertise, resulting in prohibitive costs and operational complexity. Consequently, many companies—particularly SMEs—are unable to perform systematic RF material characterization and are forced to rely on poorly specified or non-RF-grade materials, leading to suboptimal designs, increased development risks, and reduced innovation capacity.
The RFmatCarac project builds directly on the results of the ERC Consolidator Grant ScattererID, which introduced a new analytical framework linking the resonant behavior of chipless RF scatterers to the electromagnetic properties of their environment. RFmatCarac aims to exploit and valorize this ERC-funded research by demonstrating the feasibility of a radically new, wireless approach to dielectric characterization. The proposed method relies on simple, fully metallic resonant scatterers placed directly on or within the material under test and interrogated using a radar-like measurement principle. By extracting the resonance frequency and quality factor from the backscattered signal, the complex permittivity can be determined analytically.
The overall objective of this project is to reduce both the technical and economic barriers to RF dielectric characterization. The project has validated the approach across a broad frequency range and for a wide variety of materials, including solids and powders.
