High-powered microwave transmitter transmits 1.6 kW through the air over a distance of one kilometer

In what it describes as the largest demonstration of its kind in half a century, the US Naval Research Laboratory transmitted energy with a power greater than 1 kW over one kilometer using a beam of micro- waves.

SCOPE-M technology

The idea of ​​transmitting energy through the air over long distances is far from new. By the 1970s, the technology was mature enough to make it a key part of the American physicist’s concept Gerard K. O’Neillwhich proposed to establish space colonies in order to build huge stations capable of capturing solar energy and returning it to Earth.

The principle is relatively simple. The electricity is converted into microwaves, which are then focused via a narrow beam onto a receiver incorporating tens of thousands of antennas whose frequency band is in the microwave radio region of the electromagnetic spectrum, coupled to rectifier diodes for converting the incident microwave power into direct electrical power.

Using a 10 GHz microwave beam, the technology SCOPE-M was tested on a US Army base in the Marylandas well as at Massachusetts Institute of Technology, and the results exceeded expectations. In the context of transmissions over a distance of one kilometer, the researchers recorded a peak power of 1.6 kW, proving to be 60% higher than the objective initially set by the Pentagon.

A safe frequency

This frequency was chosen because it can be transmitted in heavy rain with less than 5% power loss, and meets international safety standards (it is safe for birds, animals and humans).

According to the researchers, the technology SCOPE-M could one day be used to transmit energy on Earth or from large orbital solar power plants to supply electricity to national grids 24 hours a day, 365 days a year. However, a more immediate application would be to transmit energy directly to troops in operation, eliminating the need for particularly vulnerable fuel convoys.