NTT DOCOMO has developed an antenna system capable of creating a high-frequency mobile communication cell when a small (roughly one cubic centimeter) piece of plastic is placed on top of a dielectric waveguide.
The solid plastic cube serves as an antenna by creating a "leak" from the cable to propagate signals up to several tens of meters. DOCOMO successfully tested the system with an ultra-high-frequency 60 GHz radio signal, similar to those expected to be used in future 6G networks.
DOCOMO envisions its "Drop-n-Prop Antenna" as simple, low-cost solution being used to create instant mobile environments in indoor areas not reachable with highly directional high-frequency signals propagated by outdoor base stations.
In the trial, DOCOMO constructed a communication area by running a rod-shaped dielectric waveguide made of polytetrafluoroethylene into an indoor area that was inaccessible to external mobile signals. The waveguide was embedded in a length of polystyrene-foam board with one side barely exposed to allow contact with antennas. Multiple communication cells were created simultaneously by placing antennas along various parts of the waveguide. Signal coverage and direction were controlled by changing the material, shape and positioning of the antennas.
Both millimeter waves (28 GHz) for 5G and higher frequencies (60 GHz, etc.) expected to be used for 6G travel in very straight (rectilinear) lines. It is difficult for such waves to reach devices not in a base station's direct line of sight, or if the signals are blocked by surrounding obstacles (walls, equipment, etc.). DOCOMO's simple, low-cost antenna system being announced today merely requires a rod-shaped dielectric waveguide to be run into an area and then embedded in the floors, walls, ceilings, furniture or work surfaces. Communication areas can be constructed easily and unobtrusively in offices, factories, etc. and reconfigured quickly and flexibly just by moving the antenna(s) as required.
https://www.nttdocomo.co.jp/english/info/media_center/pr/2022/0117_01.html
