The use of 5G is premised on deployment of base stations with comparatively small coverage areas placed every few tens of meters. Given this, it will be necessary to have equipment of a compact size that can be deployed anywhere.

Conventional 5G system structures require use of an antenna panel for each terminal when simultaneously transmitting to multiple terminals. Now, by controlling with high accuracy the phase (angle) of signals separately emitted from 128 antenna elements, Fujitsu Laboratories has suppressed the interference between signals.

This enables simultaneous communications in four directions using only one antenna panel. Moreover, the company can vary signals in both horizontal and vertical directions, successfully expanding the communications area.

Fujitsu Laboratories developed a phased array chip using a technology that can regulate the phase of a signal propagated from an antenna element with accuracy of one degree or less, and built into the panel one phased array chip per eight antenna elements. The company also uses circuitry that detects the differences in phase between phased array chips, which enables highly accurate phase control for any size antenna panel that has between 64 and 256 antenna elements.

As a result, by holding the difference in undesired emissions intruding between one radio wave communicating with a device and another radio wave with another device to 20dB or more, it makes it possible for a single antenna panel to carry out high-capacity communications of 10 Gbps or more. Detecting the phase differences from the signals produced by each antenna element and controlling the phase with high accuracy to concentrate the signal in the desired direction, these technologies successfully led to compact equipment that transmits to four users simultaneously with just one antenna panel. The compact equipment propagates radio waves on two axes, including horizontal and vertical directions, enabling wide-area communications with users.

With these developments, components can now be fit on a single 13 cm2 printed circuit board, instead of two or more antenna panels required with conventional technology. This will enable the deployment of compact base stations and high-speed 5G communications in locations where many people gather, such as around train stations and in stadiums.