Diffuse Modular Honeycomb Passive Reflector for Efficient mmWave Propagation in Indoor Environments

This paper describes the design and prototyping of a mmWave passive reflector, in order to improve the radio propagation conditions in indoor environments when mmWave band is used. The mmWave frequency band is proposed for 6G communications, for short range and wideband scenarios, mostly indoors. The high attenuation to mmWave radio caused by obstacles and humans do not limit the applicability of this band to line-of-sight links only, since reflections and diffuse scattering on the environment surfaces contribute with some energy to the received power even for non-line-of sight. The objective of the reflector described in this paper is to reinforce such contributions in indoor environments, creating paths towards receivers that are in NLOS to the transmitter site, but focusing to obstructed areas instead of creating specular reflections. The final reflector design has a hexagonal shape that allows it to be mechanically robust and easily assembled. It is also worth noting that it was manufactured with a simple and costless procedure, using 3D printing and metallization. The performance of the designed reflectors has been validated with measurements described in this paper.