DNP Develops Triple-Layer 5G Millimeter-Wave Array
5G shadowing with more flexible radio wave reflection angle settings
Area coverage is possible and installation space is easy to secure.


On the 31st, DNP announced the development of a Reflect Array, which flexibly reflects millimeter waves used in 5G communication systems, expanding their coverage area. Compared to standard metal reflectors, this array reflects millimeter waves in a more targeted manner, reducing installation restrictions. This improves communication in areas where radio waves are difficult to reach, such as areas obscured by buildings.

High-speed, high-capacity 5G communications radio waves above 24 GHz feature millimeter-wave bands and higher data capacity than 4G radio waves. Furthermore, their directivity and short range make them difficult to maintain communication quality in areas such as buildings, where signals are blocked. To address this, new base stations and repeaters are being installed, but this increases the burden and occupies limited space.

DNP developed a reflective array that separates the Frequency Selection Reflection Layer, which selectively reflects certain frequency bands while allowing other radio waves to pass through, and the Reflective Direction Control Layer, a special inductive layer that determines the inflow and reflection paths of radio waves, and allows for easy management of the characteristics of each layer. It costs less than installing a base station or repeater, and does not require a power source, so it can be installed in various areas.

Unlike metal reflectors that directly reflect radio waves like a mirror, this reflective array asymmetrically reflects radio waves of a specific frequency range. It can flexibly set the frequency range to be reflected, the angle of incidence of radio waves received from the base station, the angle of reflection to transmit radio waves, and the propagation of the reflected waves, so it can effectively transmit radio waves to areas where radio waves were difficult to reach.

DNP's reflective array consists of a triple-layer structure: a frequency selective surface layer (FSR), which selectively reflects a set frequency range while allowing other waves to pass through; a reflective direction control layer (DCR), which determines the inflow and reflection paths of waves; and a design cover layer. Various patterns can be printed on the surface of the design cover layer, allowing for the addition of external designs.

A growing number of companies and organizations are adopting 5G to implement smart cities and smart factories utilizing robots and the Internet of Things (IoT). DNP anticipates that Reflect Arrays will continue to be installed in the following scenarios and locations where radio conditions are expected to deteriorate due to obstacles, and is exploring ways to integrate them with various 5G initiatives.

DNP Reflect Array was selected as a Japanese national project for fiscal year 2021, and its functions will be verified in collaboration with various telecommunications companies, with commercialization planned for fiscal year 2023.