Short Name: HFCircuits, Project Number: SIB62

Metrology for new electrical measurement quantities in high-frequency circuits

New measurements for emerging electronics: Benchmarking high-performance, energy-efficient electronics 

Coordinator: Nick Ridler (NPL)

From laptops and smartphones to security scanning and medical diagnostics, many devices now require radio-frequency (RF) electronic circuits to operate. As demand for higher data rates grows, existing RF systems and devices incorporating new materials (graphene, for example) need testing at ever higher performance levels. The vector network analyser (VNA) is the key instrument used to assess RF systems and components such as the waveguides that are used for signal transmission. To achieve the higher measurement accuracies needed by industry, new and improved calibration methods are required which are traceable to the SI units.


This project developed traceable calibration methods for RF electronics measurements, including hardware for the characterisation of VNAs, waveguides, non-linear amplifiers in 5G communications, and RF components with “extreme” impedances (based on new materials such as graphene).


The project developed:

  • Traceable test methods and reference devices to characterise the high frequency waveguides that are used for signal transmission in electronic devices
  • A reference printed circuit board (PCB) to enable the removal of testing contributions from assessments of electronic circuits. This demonstrated the feasibility of PCB integration into other circuitry for built-in, ongoing device performance monitoring
  • A reference device enabling large-signal distortions to be quantified during high-power transmissions, which is important during 5G communication amplifier prototyping.


This project has successfully developed calibration methods and reference devices to help meet the current and emerging requirements of radio frequency (RF) device manufacturers. The project’s VNA calibration methods and best practice information have been incorporated into a recent revision of the EURAMET Calibration Guidelines No 12. To address problems caused by poor component compatibility, the project investigated connection sizing issues and results from these studies have contributed to a new series of IEEE standards (the 1785 series).


These are significant steps towards the introduction of greater measurement harmonisation in RF electronics. Newly available measurement services for the traceable calibration of RF transmission components (coaxial lines and waveguides) will also support developing RF technologies such as 5G communications. Building on these achievements, further EMPIR funding was subsequently secured for the follow-on projects 14IND10 Metrology for 5G communications (MET5G), and 14IND02 Microwave measurements for planar circuits and components (PlanarCal). In addition, EMPIR projects 17SIP04 Trove17SIP06 FAME VNA and 17SIP08 NeWITT build on the work of this project.

Participating EURAMET NMIs and DIs

CMI (Czech Republic)

LNE (France)

METAS (Switzerland)

NPL (United Kingdom)

PTB (Germany)

RISE (Sweden)

VSL (Netherlands)

Other Participants

Keysight Technologies Belgium (Belgium)
Rohde & Schwarz GmbH & Co. Kommanditgesellschaft (Germany)


SI Broader Scope
2013 - 2016
Researcher Grants
Project website

Measurement comparison up to 65 GHz in coaxial 1.85 mm line

Proceedings of the Conference on Precision Electromagnetic Measurements

Verification concepts in S-parameter measurements

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Effects of Connectors and Improper Mounting of Air Lines in TRL Calibration

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Traceable DC - 18 GHz Characterization of Coaxial 50 ohm Impedance Standards

2016 Conference on Precision Electromagnetic Measurements (CPEM 2016)

Traceable Calibration with 1.0mm Coaxial Standards

2016 87th ARFTG Microwave Measurement Conference (ARFTG)

A Nonlinear Verification Device for Nonlinear Vector Network Analyzers

Proceedings Conference on Precision Electromagnetic Measurements 2016

Uncertainty Evaluation of Balanced S-Parameter Measurements

Conference on Precision Electromagnetic Measurements, Ottawa, Canada, 10 – 15 July 2016

Comparison of Calibration Methods for Multiport VNAs up to 67 GHz

Conference on Precision Electromagnetic Measurements, Ottawa, Canada, 10 – 15 July 2016 (CPEM 2016)

Investigating correlations in frequency-domain S-parameter measurements

Proceedings 87th ARFTG Microwave Measurement Conference

A study of the reference impedance influence on a TRL calibration

Proceedings 87th ARFTG Microwave Measurement Conference

Impact of measurement uncertainty on modelling

Proc. of 21st International Conference on Microwave, Radar and Wireless Communications (MIKON)

Traceable High Impedance Calibration Standards

87th ARFTG Microwave Measurement Conference (ARFTG)

Radiation of the coaxial-microstrip transition in precise microwave measurements

43rd meeting of the Czech elektrotechnical society

Comparison of methods for measurement of equivalent source match

Proceedings of the 45th European Microwave Conference

Investigation of Verification Artifacts in WR-03 Waveguides

Journal of Infrared, Millimeter, and Terahertz Waves

Calibration/Verification Standards for Measurement of Extremely High Impedances

Proc. of the 86th Microwave Measurement Conference (ARFTG)

Microstrip open: Problematic calibration standard

Proc. of the 85th Microwave Measurement Conference (ARFTG)

Investigation of verification artefacts in rectangular waveguides up to 325 GHz

Proceedings Radio Science Conference (URSI AT-RASC), 2015 1st URSI Atlantic

A calibration procedure for electronic calibration units

84th ARFTG Microwave Measurement Conference

3-D Printed Metal-Pipe Rectangular Waveguides

IEEE Transactions on Components, Packaging and Manufacturing Technology

Steady-state Skin Effect in Multilayer-Conductor Coaxial Lines

Proceedings of the 44th European Microwave Conference 2014

Use of reduced aperture waveguide as a calculable standard for the verification of millimetre-wave vector network analyzers

Proceedings of the 44th European Microwave Conference, Rome, Italy, 5 – 10 October 2014

Reconfigurable Waveguide for Vector Network Analyzer Verification

IEEE Transactions on Microwave Theory and Techniques

Residual Error Analysis of a Calibrated Vector Network Analyzer

Microwave Measurement Conference (ARFTG)

A Method for De-Embedding Cable Flexure Errors in S-parameter Measurements

Microwave Measurement Conference (ARFTG), 2014

Study of calibration standards for extreme impedances measurement

Proc. of the 83rd Microwave Measurement Conference (ARFTG)

Reduction Technique for Measurement Comparisons with Complex-Valued Measurands

Proceedings on 29th Conference on Precision Eletromagnetic Measurements

Characterizing Cable Flexure Effects in S-parameter Measurements

Microwave Measurement Conference, 2013 82nd ARFTG