Research activities on millimeter wave indoor communication systems in Japan

R&D activities on millimeter-wave indoor communication systems in Japan are described. Attention is given to millimeter-wave propagation characteristics, a system study of indoor communications in offices, and the development of active devices such as MMICs (monolithic microwave integrated circuits) and flat antennas. A comprehensive research program on millimeter-wave indoor communication technologies, including propagation, antimultipath techniques, and antennas, was recently initiated. In the first step, a 60-GHz indoor propagation experimental system with a delay-time resolution on the order of 1 ns, based on a frequency sweep technique, was developed, and measurements of indoor multipath propagation and reflection properties of interior construction materials have been conducted. The 60-GHz system configuration and the major system characteristics are shown.<>