Development of RF and microwave metrology capability

The EU produces 20% of global industrial electronics which in 2019 accounted for €301 billion in production and directly impacted €3.8 trillion in European GDP.

Almost all electronic devices emit low-power radio frequency (RF) and microwave (MW) fields. These emissions may interact adversely with other nearby electronics causing distortions or harmonics, resulting in degraded performance or impaired function.

Electromagnetic compatibility (EMC) testing determines the interaction of electrical equipment with the electromagnetic environment and immunity tests measure a devices ability to withstand RF&MW interference. Both tests are required by a manufacturer before releasing a product onto the market. EMC test instruments rely on accurate ‘Scattering parameter’ (S-parameter) measurements describing the behaviour of electrical networks when undergoing steady state stimuli by electrical signals. For EMC testing equipment this value is obtained through comparison with calibration standards. However, this simplified approach was insufficient for more advanced RF&MW components.

In the RF&MW field, less developed European NMIs were unable to perform many of the required calibrations of instruments to allow measurements to be linked to the SI including high-power measurements (≥ 1 W) and for device components that generated low power (≤ 0.01 mW).

An improved knowledge in RF&MW measurements was required to decrease the capability gap between countries and help maintain European competitiveness in this area.

To address the need for improved S-parameter measurements project partner METAS developed a new ‘just-before-test’ verification method. Using a specialised Vector Network Analysis (VNA) software tool hidden issues were detected prior to conducting emission and immunity tests and, for the first time, was extended to low-frequency immunity testing to increase the quality of ECM measurements. Personnel at CMI, INTA, SIQ, RISE, NIS, NQIS, GUM and TUBITAK UME were trained to perform this test. ECM measurements of the project partners were further improved through the development of a traceable ‘loop antenna’ calibration technique using VNA and a pulse generator.

The project also focused on traceability with respect to the calibration of sensors for low-power measurements and power sensors were characterised at GUM, SIQ, NQIS, NIS and INTA based on the experience of TUBITAK and CMI. To further disseminate the knowledge gained to other measurement institutes six good practice guides were produced. Improved calibration services for low power and S-parameter measurements have been established in Europe in the RF&MW area and the link between EMC and RF&MW laboratories more firmly established.

These findings enable European Laboratories to control the EMC performance of products more precisely, helping Europe maintain its market position in this area.