06/10/2021

The International Amateur Radio Union (IARU[1]) represented the Amateur Service
at a recent International Telecommunication Union (ITU) recent virtual meeting
on the topic of wireless power transmission (WPT), attended by some 350
delegates. ITU Working Party 1A Working Group WG1A2 was of most relevance to
IARU, covering the topic of WPT. The focus is on WPT's impact on the radio
spectrum.

IARU contribution centered on proposing amendments to material submitted by
other delegations and a new annex that documents measurements of typical
amateur signal levels, comparing these to test data from the US on non-beam WPT
emission levels and to suggested limits.

"Most of the discussions on the detail were resolved with a degree of
compromise, and the latest drafts will be attached to the chairman's report for
the meeting," IARU Region 1 reported. Remaining technical issues include:

" Whether E-field antennas are as susceptible to WPT-EV (WPT Electric Vehicle)
emissions as H-field antennas.

" The true noise levels in residential areas, with WPT developers claiming that
WPT emissions will not be significantly above the (now-elevated) noise level.

In terms of the E-field sensitivity to WPT emissions, the proposed work plan
submitted by IARU to the European Commission, for WPT-EV tests in the Joint
Research Centre, included proper E- and H-field measurements.

"IARU member-society DARC [Germany] has made good progress with the rollout of
its ENAMS automated noise measurement system, and IARU is now able to draw
heavily on that data," IARU Region 1 said. "The WPT Emissions document has been
under discussion for some time. Here, there is no agreement yet on whether this
should be a Report or a Recommendation, and the work has been carried forward
to the next meeting in November 2021."

Discussion on so-called "beam" WPT covered a range of issues, including
amendments to the proposed frequencies (none are below 800 MHz). "Sadly, many
proposed frequencies fall in spectrum which the Amateur Service shares with
other services," IARU said. "However, given the nature of the technology and
the directivity of amateur antennas in these frequency ranges, the prospect of
coexistence seems quite good."

IARU has provided extensive input on the potential impact on radio
communications resulting from spurious emissions from WPT devices. Given the
planned density of WPT systems for electric vehicles operating in the 79 - 90
kHz range, widespread interference could occur to Amateur Service stations in
the vicinity of WPT systems. 

[1] http://www.iaru.org

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