18SIB09 TEMMT: Traceability for electrical measurements at millimetre-wave and terahertz frequencies for cummincations

• Forschungsstelle: METAS
• Projektnummer: F-5217.30125

Schlüsselwörter (Englisch)

Traceability, millimetre-wave, terahertz frequencies, electronics technologies

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Kurzbeschreibung (Englisch)

This project aims to establish traceability to the SI for 3 electrical measurement quantities; (i) S-parameters, (ii) power and (iii) complex permittivity of dielectric materials, at millimetre-wave and terahertz (THz) frequencies. Such traceability is important for many emerging applications, exploiting communications and electronics technologies – e.g. 5th Generation mobile networks (5G), the Internet of Things (IoT), Connected and Autonomous Vehicles (CAVs), space-borne radiometers for Earth remote sensing, and security imaging, etc. The goal of this project is to support such emerging application and enable European NMIs to provide traceability to the SI for these 3 parameters in the millimetre-wave and THz part of the spectrum, which will be beneficial to end-users.

This is a joint research project carried out in the framework of the European Metrology Programme for Innovation and Research (EMPIR) (see:http://www.euramet.org/research-innovation/empir/). The EMPIR initiative is co-funded by the European Unions's Horizon 2020 research and innovation programme and the participating states. METAS is one of the project partners in the project.

Projektziele (Englisch)

The overall objective of this project is to achieve accurate and traceable electrical measurements for users of the millimetre-wave and THz regions of the electromagnetic spectrum, particularly for electronics applications impacting future communications technologies – so-called 5G communications and beyond.

The specific objectives of the project are:

1. To develop metrological traceability and verification techniques for S-parameters (that measure the loss and phase change for transmitted and reflected signals) in both coaxial line (using the 1.35 mm E-band connector to 90 GHz) and rectangular metallic waveguide (using waveguides covering frequencies from 330 GHz to 1.5 THz). Three waveguide bands within this frequency range will be covered and these are 330 GHz to 500 GHz, 500 GHz to 750 GHz, and 1.1 THz to 1.5 THz.
2. To develop metrological traceability and verification techniques for S-parameter measurements on planar substrates from 110 GHz to 1.1 THz. Three waveguide bands within this frequency range will be covered and these are 110 GHz to 170 GHz, 500 GHz to 750 GHz, and 750 GHz to 1.1 THz.
3. To develop metrological traceability for power measurements in waveguides to 750 GHz. Two waveguide bands within this frequency range will be covered and these are 110 GHz to 170 GHz, and 500 GHz to 750 GHz.
4. To develop metrological traceability for complex permittivity of dielectric materials to 750 GHz. Two waveguide bands will be covered and these are 140 GHz to 220 GHz, and 500 GHz to 750 GHz.
5. To facilitate the take up of the technology and measurement infrastructure developed in the project by other NMIs with the view of forming a coordinated network of NMIs that provide a comprehensive measurement capability as well as by the measurement supply chain (research institutes, calibration laboratories), standards developing organisations (e.g. IEEE P287 and IEEE P1785) and end users (i.e. manufacturers of telecom equipment, measuring instruments, absorber materials, etc).

Abstract (Englisch)

In January 2021 we measured the set of nine reference materials for the material measurement comparison (EURAMET pilot study). From the complex transmission data and the previously determined specimen thickness values, the material parameters have been extracted via the standard method for all materials. In this standard method the Fresnel transmission coefficient equation is inverted to get the complex refractive index. From the complex refractive index all other material properties like the permittivity or the absorption coefficient can be determined.

First material parameter comparisons with available data from other partners have been carried out. From these comparisons, we see that there is a good general agreement between the different partners. However, for some materials like high-resistivity silicon, we should be able to get better results by applying other material parameter extraction methods or using some a priori knowledge of the optical properties.

Furthermore, we have managed the shipment of the set of reference materials and calibration artefacts between the different partners. METAS thereby serves as pivot institute since, due to customs reasons, all shipments start or end at METAS. In addition, we have acquired another partner that participates in the pilot study with a unique optical setup, namely a THz ellipsometer (group of Christian Bernhard, University of Fribourg).