In this paper, we present a comprehensive uncertainty budget for on-wafer S-parameter measurements of devices on a custom-built fused silica wafer, including instrumentation errors, connector repeatability, and calibration standard uncertainties. All major steps toward achieving traceability with the aid of a multiline thru-reflect-line calibration for the given measurement scenario are explained. For the first time, it is now possible to compare against each other the relative importance of different sources of uncertainty in on-wafer measurements. Results are shown for three typical devices with varying reflection and transmission characteristics.

The millimeter-wave (mm-wave) and terahertz (THz) regions of the electromagnetic spectrum are seeing increasing prominence, with a range of established and emerging applications—wireless backhaul for mobile networks for 5G and 6G infrastructure, automotive radar sensors, space-deployed radiometers for Earth observation, climate monitoring, weather forecasting, and more—exploiting these frequencies. Measurement techniques informed by the latest metrological research into the measurement of electrical quantities underpin the development of components and circuits for such applications by enabling the accurate and consistent measurement results to be obtained.

This article presents the design, fabrication, and characterization of a D-band (110–170 GHz) bolometric power sensor, used for millimeter-wave metrology. This sensor type is new thin-film-based sensor, which consists of a multilayer chip embedded in a silicon substrate as a microwave absorber. The sensor demonstrates reasonable performance with a return loss of better than 15 dB across the entire D-band and the rise and fall times better than 1.8 ms. The sensor achieves high power linearity between −10 and +8 dBm. Frequency response of the sensor was measured, and its flatness changes no more than 20% across the frequency band. Furthermore, this power sensor has been characterized in the microcalorimeter, and an effective efficiency of over 90% could be achieved. For the first time, the design, fabrication, and characterization of a novel power sensor prototype with excellent performance at D-band are presented.

This article reports on an extensive interlaboratory comparison of measurements of material properties between 2 GHz and 1 THz using both vector network analyzer (VNA)-based and optical-based methods. For the former, techniques including open resonators, conventional free-space quasioptical systems, and a relatively new guided free-space approach through use of material characterization kits (MCKs) were utilized. The optical-based methods included both time-domain spectroscopy (TDS) and frequency-domain spectroscopy (FDS). Measurement setups for these five techniques located at five well-established laboratories have been employed in the measurements of seven types of commonly used dielectric materials. The results of the measurements by the participating laboratories using each of these techniques were compared to assess levels of agreement between the utilized techniques and thereby establish confidence in the characterizations of each material. Measurement results of these seven materials are presented, together with detailed discussion. This is the first time that an interlaboratory measurement comparison of material properties has been conducted over nearly three decades of frequency and involving such a range of techniques. This work should prove beneficial to applications where material properties need to be known accurately in the microwave to terahertz region.

As part of a joint program three National Measurement Institutes around Europe—the National Physical Laboratory in the UK, the Physikalisch-Technische Bundesanstalt in Germany and the Laboratoire National de métrologie et d’essais in France—have each established new capabilities for the traceable measurement of S-parameters up to 90 GHz in the new 1.35 mm (E band) coaxial connector. Each institution has established their own measurement systems to access the full frequency band for the connector, utilising a variety of commercially available equipment and measurement setups. Each have also developed their own calibration techniques and verification methods using different vector network analyser calibration routines. These include optimised multi-line Through Reflect Line, multiple Offset Shorts Through and Short Open Load Reciprocal (SOLR) schemes. Uncertainties for each of these setups and calibration schemes were determined utilising theoretical models of the systems and calibration standards, or through verification methods, with different effects being derived from the dimensional characteristics for each of the different standards or verification artifacts. The different dimensional systems used to make these measurements were also developed and established previously as part of the same program. The last part of this exercise was a three-way intercomparison between the laboratories. The comparison involved the measurement of a set of four traveling standards, including both 1-port and 2-port as well as plug (male) and jack (female) devices, each with different reflection and transmission characteristics to better test and demonstrate the equivalence of the capabilities.