New Chip Cancels On-Channel RF Interference

A postgraduate student at Enschede, Netherlands’ University of Twente has developed a chip using four individual receivers to cancel on-channel interference. The device, created by student Michiel Soar, has inputs for four antennas, each with its own adjustable delay circuit, and a combiner to sum the delayed signals from the four antennas. By adjusting the delay on each input to the combiner, an interfering signal can be canceled. Soar's chip has the ability to change the delays as the signals change, as would happen in a mobile or portable receiver or if an objecting reflecting one of both of the signals (truck or airplane, for example) moved. The principle isn't new, but until now it was difficult and expensive to implement. Soar's chip has all the elements needed for a smart beamforming antenna array on one chip, allowing it to be manufactured "extremely economically and cheaply" according to the University of Twente.

The University of Twente news release University of Twente develops antenna capable of remedying malfunction offers little technical detail and is a bit difficult to understand until you substitute "interference" for "malfunction" in the English translation.

For a better explanation of how the chip works, including a lab demonstration, see the YouTube video Antenna Beamforming for Wireless Communications. In the video it appears that the chip is able to reduce a significantly stronger interfering signal to a level roughly 20 dB below that of the desired signal. The system does not appear to require any special coding of the signals to achieve the interference reduction and works even when the interfering transmitter is close to the desired transmitter.

Bram Nauta, a professor in Integrated Circuit Design at the University of Twente, said, "The product will probably be available on the market within two years." The University is a participant in the STARS ("Sensor Technology Applied in Reconfigurable Systems") project along with NXP, Thales and TNO so I would expect to see the technology commercialized by one of these companies.

More information is available on the RF Lab at the University of Twente and on Michiel Soar's homepage.

Doug Lung

Doug Lung is one of America's foremost authorities on broadcast RF technology. As vice president of Broadcast Technology for NBCUniversal Local, H. Douglas Lung leads NBC and Telemundo-owned stations’ RF and transmission affairs, including microwave, radars, satellite uplinks, and FCC technical filings. Beginning his career in 1976 at KSCI in Los Angeles, Lung has nearly 50 years of experience in broadcast television engineering. Beginning in 1985, he led the engineering department for what was to become the Telemundo network and station group, assisting in the design, construction and installation of the company’s broadcast and cable facilities. Other projects include work on the launch of Hawaii’s first UHF TV station, the rollout and testing of the ATSC mobile-handheld standard, and software development related to the incentive auction TV spectrum repack. A longtime columnist for TV Technology, Doug is also a regular contributor to IEEE Broadcast Technology. He is the recipient of the 2023 NAB Television Engineering Award. He also received a Tech Leadership Award from TV Tech publisher Future plc in 2021 and is a member of the IEEE Broadcast Technology Society and the Society of Broadcast Engineers.