Measuring the material parameters with a vector network analyzer (VNA) usually requires time-domain gating and complicated free-space calibrations. At terahertz frequencies, classic calibrations become more problematic and uncertainty calculation for time gating is not clearly defined. The here investigated method skips these steps and is based on normalization to a “Thru” connection and analyzing error terms and multiple-reflection phenomena (ripples). It is shown that at specific frequencies, the ripples are very small. Based on this, the “standard load” method is introduced, which simplifies the error correction for transmission and reflection measurements for the whole frequency range. Results are presented in 75-110- and 500-750-GHz bands with a quasi-TEM free-space setup. Various material slabs (thin, thick, lossy, and low-loss) have been tested to show the reliability and general usefulness of the method. This method that is initially based on a “Thru” connection only provides a simple and low-cost alternative to the conventional standards (Line, Match, Short, and so on) and calibration techniques.

The accuracy of S-parameter measurements can be improved by replacing calibration kits for industry grade connectors by a combination of one calibration kit for metrology grade connectors and well characterized adapters. This paper compares two methods to characterize such adapters which join metrology grade coaxial connectors with industry grade connectors. A first method employs a thru connection as well as opens and shorts with industry grade interfaces to obtain the full S-parameters of an adapter. The second method uses beadless adapters rather than opens and shorts. It is shown that the second method is superior in particular for frequencies above 30 GHz.

This paper presents METAS VNA Tools Version 2.9.0, a metrology software suite designed to support the digital traceability chain in vector network analyzer measurements. Built on the METAS UncLib Version 2.9.0 uncertainty engine, the software enables rigorous modeling of the entire measurement process and comprehensive uncertainty evaluation. By encapsulating values, dependencies, and sensitivities in structured uncertainty objects, the software ensures that traceability and correlation information are preserved and propagated throughout complex calibration chains. This approach allows for seamless, modular uncertainty evaluation and supports the generation of digitally signed calibration certificates with embedded calibration data. The methodology enhances transparency, reproducibility, and interoperability, aligning with the goals of digital transformation in metrology. VNA Tools thus provides a robust foundation for implementing traceable, data-driven workflows across all levels of the metrological infrastructure.

METAS VNA Tools is a metrology-grade software suite developed to facilitate measurements using vector network analyzers. Its uncertainty analysis is founded on a comprehensive modeling of the entire measurement process and is implemented through multivariate uncertainty propagation via the METAS UncLib library, in accordance with GUM and EURAMET guidelines. Engineered to ensure traceability and compliance with ISO/IEC 17025, VNA Tools has been widely adopted by national metrology institutes, as well as calibration and industrial laboratories, owing to its robustness, transparency, and scientific rigor. As it is freely available, the software serves not only as a tool for the dissemination of calibration data but also enables advanced post-processing. Consequently, it provides added value that extends beyond the mere generation of calibration certificates, reinforcing both the seamlessness and integrity of the traceability chain.

The objective of the here introduced method is to determine the linearity errors of each receiver in a vector network analyzer. By varying the source power and using different devices under test, one can identify these errors. Subsequently, the linearity errors of each receiver are used to estimate linearity errors in attenuation measurements. The application of this method resulted in upper bounds for relative linearity errors of 0.005 dB within an amplitude range of up to 50 dB at a frequency of 50 GHz.