The IARU watches WPT developments

January 8th, 2018 by AJ4MQ

The WIA report widespread interest continues in Wireless Power Transfer (WPT) technology, reflecting the considerable concern about its potential to cause radio frequency interference.

Studies continue ahead of the World Radiocommunications Conference 2019 with its Agenda item 9.1.6 - Wireless Power Transmission (WPT) for electric vehicles.

WPT applications are expanding to mobile and portable devices, home appliances and office equipment. The automotive industry looks to it for electric vehicle applications in the near future.

Power levels range from milliwatts to hundreds of kilowatts and typical transmission ranges are up about 30 centimetres. But news from India is that scientists using a nanogenerator can harvest mechanical energy such as people walking on a footpath, and convert it into electrical energy. The electricity is transferred wirelessly over a distance of three metres to a storage device like a battery.

Radio users are concerned that while the intended distance can be small, it is inevitable that some energy will be coupled into other conductors acting as unintended antennas. This may cause harmful interference to incumbent services through the radiation of harmonics.

WPT is recognised as having potential advantages but must develop in such a way that prevents harmful interference to incumbent services in the frequency band or bands to be considered. Protection of incumbent in-band radiocommunication services as well as adjacent and harmonically related bands from spurious and out-of-band emissions must also be ensured.

Wireless Institute of Australia