Dept. Environment Communications : Projects

Boost of Satellite Communication by Poly-Polarization Multiplexing

There has recently been a large increase in the use of satellite data communications and, at the same time, they have received much interest as part of an emergency communications infrastructure in the event of natural disasters. As a countermeasure, the orthogonal polarization multiplexing method for multiplexing signals onto both vertical and horizontal polarizations has been considered, although the number of multiplexed signals ultimately remains at two. With the aim to further improve the frequency utilization efficiency, a poly-polarization multiplexing transmission system has been proposed. Using this technique, we can increase the spectral efficiency further by simultaneously using multiple polarizations i.e. greater than two. However, as the earth station to satellite transponder is considered a line-of-sight propagation channel, we have had to investigate and apply different techniques to those of traditional MIMO in order to recover the signals.

High Efficiency Energy Harvesting Technology from Electromagnetic Waves

A high-efficiency energy harvesting system is needed in order to generate usable electric power from various electromagnetic waves, e.g. the cellular and the broadcasting signals, in the living space. To achieve this, we have developed a triple band antenna panel of 1 m2 that employs an optimal antenna array layout, highly-efficient antennas and circuits. The developed panel has achieved more than 100μW of power generation at 1.5V under a defined environment. This is the world’s leading conversion efficiency. In addition, we have succeeded in continuous operation of a LCD thermometer with the harvested energy in the real environment.

Developed energy harvesting antenna panel

Other ongoing projects
・ Strategic Information and Communications R&D Promotion Programme(SCOPE)
“R&D on Low-Latency Multiplexing Communication System for In-Machine Wireless Harness”
・ Several nongovernmental funds

≫Wireless communication eliminates the wiring in equipment
≫Toward the materialization of gigabit class ultrafast wireless LAN

ATR Wave Engineering Laboratories