From sensor to microcalorimeter: Traceable power measurement at terahertz frequency

Professor Dr Xiaohai Cui (National Institute of Metrology (NIM), P R China)

Abstract – Power is one of most important parameters in RF metrology. Microcalorimeters are the most accurate apparatus at present which can work as the national primary standard and provide traceability for RF power measurements. NIM developed the transfer standards (thermo-electrical power sensor) and microcalorimeters for WR-06 (110 GHz to 170 GHz) and WR-05 (140 GHz to 220 GHz) in 2017 and 2018, respectively. Currently NIM can provide power sensor calibration from 10 MHz to 220 GHz with direct traceability to the primary power standards maintained at NIM. In this presentation, the principle of the transfer standards, microcalorimeters, measurements results and uncertainty evaluation will be reported.

Biography – Xiaohai Cui received the B.S. and Ph.D. degrees in electrical engineering from the Beijing Institute of Technology, Beijing, China in 1996 and 2004, respectively. He joined the National Institute of Metrology (NIM), P. R. China, in 2004. During 2007, 2008 and 2017, he worked in the Electromagnetics Division at NIST, USA, as a guest researcher. His primary research interest is microwave power standards and microwave power measurement. He is very active in participating and organizing international comparisons of RF power measurements. His current research is aimed at primary power standards from 10 MHz to 330 GHz. Dr. Cui is also a professor at the Beijing University of Posts and Telecommunications, and was a recipient of the Science and Technology Award of the third class from the Local Beijing Government of China in 2011, the Electronic Information Science and Technology Award of the second class from the Chinese Institute of Electronics in 2012, and NIM’s Science and Technology Award of the first class (first place) in 2014.

Terahertz High-Resolution Gas-Phase Spectroscopy

Prof Brian Ellison (Rutherford Appleton Laboratory, UK)

Abstract – Application of terahertz technology to the characterisation of spectral signatures originating from gaseous sources will be presented. Particular reference will be made to passive remote sensing of molecular emissions that naturally occur within Earth’s atmosphere, the large gaseous planets of our solar system, and the interstellar medium. Relevant system detector architectures will be introduced, primarily focussing on heterodyne frequency down-conversion, and the salient features noted, including examples of ground-based, airborne and spaceborne instrumentation. Potential for exploitation via laboratory-based systems will also be discussed.

Biography – Brian Ellison (CEng, FIET) leads the Millimetre-wave Technology and Chilbolton Radio Observatory Group within Rutherford Appleton Laboratory Space Department (RAL Space), UK. He began his career at Chilbolton Observatory and developed microwave instrumentation in support of radio astronomy. Moving to the California Institute of Technology, USA, he developed terahertz receivers for astrophysics research. Returning to the UK, and RAL, he continued with terahertz research and simultaneously undertook the role of UK Project Manager for the Atacama Large Millimetre/submillimetre Array (ALMA) during its construction phase. Brian is a visiting professor within The Open University Faculty of Science, Technology, Engineering and Mathematics.

Feasibility of Accurate Power Measurement in Submillimeter/mm-Wave Domain Based on Free-Space Techniques

Dr Alireza Kazemipour (METAS, Switzerland)

Abstract – The development of high quality and safe products and systems in mm-Wave/THz range depends on the availability of traceable measurement capabilities. Present RF-power (established) standards are generally coaxial and waveguide thermal detectors which can cover the frequencies up to 110GHz. Calorimetric methods are often used to calibrate the sensors at primary-level directly traceable to International System of Units (SI).

For higher frequencies where the small mechanical dimensions of the metallic waveguides are problematic, free-space techniques could be of benefit. Open-surface detectors like photo-acoustic, pyroelectric, bolometer-array … (traditionally used in IR/Optical measurements) can be characterized at sub-THz frequencies. The main challenge is to suit a waveguide source to the sensitive open-surface of the Optical/THz detector with a high-directivity antenna and to establish a reliable scattering model of the antenna and detector.

Biography – Alireza Kazemipour received the B.Sc. degree in Electronics and Telecommunications from Sharif University of Technology, the M.Sc. degree in Physics from Tehran University, Iran, and Ph.D. from Telecom-ParisTech, France, in 2002. He was an Associate Professor in Korea and Malaysia and a senior scientist with the European National Institutes of Metrology NMIs 2002-2018. He is currently with The Federal Institute of Metrology (METAS), Bern – Switzerland.

Measurements of S-parameters and material properties at millimetre-wave and terahertz frequencies

Dr Xiaobang Shang (National Physical Laboratory, UK)

Abstract – There is an increasing demand for accurate and traceable electrical measurements for devices and integrated circuits operating at millimetre-wave and terahertz frequencies. This is driven by a range of applications including 5G, Internet of Things (IoT), Connected Autonomous Vehicles (CAV), space-borne radiometers for Earth observations, and security imaging, etc. A European project, entitled “TEMMT”, is devoted to tackling the measurement challenges at these high frequencies and to establishing traceability for three electrical measurement quantities: S-parameters, power, and material properties. This talk will give an insight into this large scale European project which involves 19 partners across the world. This talk is also intended to summarise the research and development at the UK’s National Physical Laboratory (NPL) for measurements of S-parameters and material properties at millimetre-wave and terahertz frequencies. Some latest measurement results will be presented and discussed.

Biography – Xiaobang Shang was educated at the University of Birmingham, UK, where he was awarded a PhD in 2011 for research into terahertz circuits. After graduation, he worked at the University of Birmingham as a Research Fellow.  Since 2017, he has been working at NPL as a Senior Research Scientist. He has published over 60 scientific papers on microwave measurements and microwave circuits. Dr Shang is a Senior Member of IEEE, and an executive committee member of the IET’s RF and Microwave Technology Technical and Professional Network (TPN). He was the recipient of the ARFTG Microwave Measurement Student Fellowship Award in 2009, and, the IEEE Tatsuo Itoh Award in 2017.

The design and implementation of an integrated 110GHz vector network analyzer

Dr. Baoguo Yang (China Electronics Technology Group Corporation No.41 Institute, P R China)

Abstract – At present, the measurement of S-parameters in the continuous frequency band from 10 kHz to 110 GHz is completed by using a split-type VNA, including a conventional VNA and a pair of THz modules. The bottleneck technology of integrated 110 GHz VNA includes integrated broadband signal generation, reception, transmission, and so on. In this paper, a broadband signal generation and mixing technology is introduced, a new 1 mm coaxial semi-steel cable with certain elasticity is designed, an integrated VNA is processed, and thermocouple power detection and calibration method is used. This method can increase test power, improve test accuracy and reduce test cost.

Biography – Dr. Baoguo Yang has been engaged in the analysis and testing of microwave network parameters since 2012. He has presided over 10 national or provincial projects with a total expenditure of over 100 million yuan. He has also authorized 11 Chinese invention patents and 1 international invention patent (as First inventor), published 12 papers (including as the first author and correspondence author), and formulated 4 national standards (ranked 3^rd). He is one of the Top Young Talents of the China Electronics Technology Corporation and chief engineer of the on-chip testing system.