A technical paper drafted by International Amateur Radio Union Region 1 (IARU-R1) President Don Beattie, G3BJ, is the latest official step to increase the visibility of wireless power transmission (WPT) systems’ interference threat to Amateur Radio. Submitted to the IARU-R1 Interim Meeting, set for April 27 – 28 in Vienna, the paper will update relevant committees on the topic. Beattie’s paper offers an impact analysis of WPT-electric vehicle (WPT-EV) systems on Amateur Radio communications, with a primary focus on WPT systems operating in the 79 – 90 kHz range.

“IARU engaged with discussions in CEPT [the European Conference of Postal and Telecommunications Administrations] and ITU [the International Telecommunications Union] on WPT in 2017,” Beattie’s 20-page discussion notes.

Beattie’s paper warns of “a widespread and serious impact on radio communications operating in the vicinity” of WPT systems if spurious emissions measured at a distance of 10 meters are at current CEPT Recommendation 74-01E and ITU Radiocommunication Sector Recommendation SM.329-12 limits, “given the planned density of WPT-Electric Vehicle Systems.” Both the CEPT and ITU recommendations address “unwanted emissions in the spurious domain.”

An IARU study of WPT-EV and its potential impact on radiocommunications services already has been submitted to the relevant ITU and CEPT study committees. “In CEPT, the IARU input has been carried forward in the recently published ECC Report 289,” Beattie said in his paper. Broadcasters, land mobile services, and others have also expressed concern about spurious WPT-EV emissions. “Report 289 sets out the protection requirements for these radio services, but it stops short of proposing any regulatory action,” Beattie’s paper points out. “This, therefore, is the next challenge — to seek to bridge the divide between WPT manufacturers and the radiocommunications services.”

Beattie’s paper said further work remains regarding generic WPT systems such as cell phone charging, power tools, and household appliances. “As a part of this, manufacturers have offered projections on the installed density of these devices, which allows modeling of the minimum interference field strength to be expected in an urban/suburban environment populated with WPT devices at the projected density,” Beattie noted in his paper. “This then allows IARU to make further input modeling these emissions.”

IARU provided the same input to ITU, but, Beattie’s paper says, ITU plans to include it in a separate report for discussion at a later meeting.