Very soon, all major manufacturers will start to release products with transmitters utilizing the much wider channel bandwidth that is available at frequencies above 6 GHz. At the same time, regulators and standardization committees are working hard towards defining the corresponding regulatory requirements and assessment methodology, and revising the safety guidelines to adopt to the novel exposures posed by this new technology. Due to the current regulatory uncertainty, SPEAG, with the help of the IT’IS Foundation, are pursuing with high priority the basic research and the development of a series of new instrumentation and procedures urgently needed for reliably assessing the exposure in the near field of transmitters. Based on a range of feasibility studies, we have now defined our R&D roadmap for mmWave certification tools that we would like to share with all our customers and partners in order to receive early feedback and suggestions.
The roadmap not only aims at meeting current requirements but also provides the necessary means of demonstrating compliance ahead of the upcoming safety standards (ICNIRP 2018, IEEE 2018) and the corresponding measurement and numerical assessment standards (IEC JWG 11/12) as they progress. It consists of the following main components:
cDASY6 Module mmWave V1.4 (to be released end of September 2018) comes with an improved fast search scan for optimizing the scan area and enable vertical scans for larger structures such as base station antennas. Prior to all future releases, we will continuously review the scanning strategy to further reduce the assessment time.
cDASY6 Module mmWave V2.0 (to be released end of December 2018) offers major extensions compared to Version 1.x. The first feature will allow to determine the maximum exposure configuration based on measurements only. This will be achieved by a series of powerful optimization algorithms running in parallel that allow to determine the highest possible surface-averaged power density values anywhere in space for any size and complexity of transmitter arrays. The same feature will also be made available in SPEAG’s simulation tools SEMCAD X V18+ and ZMT’s Sim4Life V5+.
cDASY6 Module mmWave V2.0 will also include a novel forward transformation method allowing to assess any exposure in 3D based on one measurement plane only. This very powerful feature will provide the means to evaluate the exposure on any virtual phantom surface (e.g., SAM-Twin, Eli, etc.).
Simulation (left) and forward transformation from measurements at a distance of 2 mm (right) of the power density in the xz (upper images) and yz-plane (lower images) for a cavity-fed dipole array at 30 GHz.
As we will support a uniquely defined coordinate system with respect to the device under test, specific absorption rate, and power density, values can be automatically combined on any surface for demonstration of compliance of devices that can transmit simultaneously on different frequency bands.
Module mmWave V3.0 (to be released in spring 2019) will not only support measurements on flat surfaces but also scanning and reconstruction on any other surface (e.g., conformal to concave surfaces and round edges). This will resolve the issue of a well-defined reproducible procedure of demonstrating devices with strongly curved surface such as virtual reality goggles.
SPEAG aims to extend our cDASY6 hardware software to enable assessment of the transmitted power density as recently proposed as basic restrictions (ICNIRP 2018 and IEEE 2018). The transmitted power density has great advantages for the manufacturers as it requires the least overestimation of the actual user exposure and thus, reduces the compliance burden of the industry without compromising safety requirements. A project has been initiated with our main research partner IT'IS to develop the necessary scientific background and instrumentation for measuring the transmitted power density, including a reliable uncertainty assessment and the corresponding validation strategy.
More details about all features are available in the report/application note “Demonstrating Compliance with Current and Future Safety Guidelines and Regulatory Requirements for >6 GHz”. cDASY6 Module mmWave V1.4 will be released by end of September and V2.0 by end of December this year, V3.0 in spring and V4.0 in autumn 2019.
We would highly appreciate your feedback on our R&D roadmap ‒ Are the proposed features sufficient for your compliance needs? Are our priorities in line with these needs? What else can we provide to accelerate the rollout of your products?