The Development of Intelligent Beamforming Antenna Systems for Stratospheric Platforms in the Millimeter-Wave Band

In this paper, we describe intelligent beamforming antenna systems that can be used in the millimeter-wave band for High-altitude platform systems. We have developed two antenna systems for the millimeter-wave band and have designed experiments to test the efficiency of the developed systems. One is a multi-beam-horn antenna that enables high-speed transmission, and the other is an array antenna that digitally controls antenna beams. These antenna systems are also designed to work in the stratosphere. We also describe our solutions to the problems of low temperature and low pressure and show that the two antenna systems can function well in the stratosphere through tests conducted on the ground.On April 1, 2004, the Communications Research Laboratory (CRL) and the Telecommunications Advancement Organization of Japan (TAO) merged to create NICT.Hiroyuki Tsuji received the B.S., M.S., and Ph.D. degrees from Keio University in 1987, 1989, and 1992, respectively. Since 1992, he has been working in the Communications Research Laboratory, Independent Administrative Institution, Japan. In 1999, he was a visiting researcher at University of Minnesota. He is now a senior researcher of Wireless Innovation Systems Group in the Yokosuka Radio Communications Research Center of NICT (National Institute on Information and Communications Technology, reorganized from CRL in April 2004). His research interests are in array signal processing, particularly as applied to communications. He received the IEICE 1996 Young Engineer Award. He is a member of IEICE and IEEE.Masayuki Oodo was born in Osaka, Japan, on February 1, 1969. He received B.E., M.E. and D.E. degrees in Electrical and Electronic Engineering from Tokyo Institute of Technology, Tokyo, Japan in 1992, 1994 and 1997, respectively. In 1997, he joined the Communications Research Laboratory (CRL, now part of the National Institute of Information and Communications Technology, or NICT), where he has been researching array antennas for wireless communication and frequency-sharing issues between HAPS and other systems. Dr. Oodo received the Paper Presentation Award from IEICE Japan in 1995, the Young Scientist Award from URSI in 1996, the Young Engineer Award from IEICE Japan in 1997, and the Young Engineer Award from IEEE AP-S, Tokyo Chapter in 1998. He is a member of IEEE.Ryu Miura received the B.E., M.E., and PhD degrees in Electrical Engineering from Yokohama National University, Yokohama, Japan, in 1982, 1984, and 2000, respectively. He joined Communications Research Lab (CRL), Ministry of Posts and Telecommunications, Tokyo, Japan in 1984, where he worked for research on mobile satellite communication systems using the Engineering Test Satellite, ETS-V. During 1991–1992, he was a visiting researcher in AUSSAT, Pty. Ltd. (now Optus, Pty. Ltd.), Sydney, Australia. During 1993–1996, he was a senior researcher in ATR Optical and Radio Communications Research Labs, Kyoto, Japan, where he worked for research on digital beamforming antennas for mobile communications. He is now a group leader of Wireless Innovation Systems Group in the Yokosuka Radio Communications Research Center of NICT (National Institute on Information and Communications Technology, reorganized from CRL in April 2004), where he works for R&D on wireless communication systems using stratospheric platforms. Dr. Miura is a member of IEEE and IEICE.Mikio Suzuki received a B.S. degree in electronic engineering from Keio University in 1970. He joined Mitsubishi Electric Corporation in 1970, where he researched and developed microwave integrated circuits and waveguide array antennas for defense radars and missiles. He is now at the NICT Yokosuka Stratospheric Platform Research Center, and his current research interests lie in the system design of applications for wireless communication systems using a stratospheric platform and the development of related communication equipment. He is a member of the IEICE of Japan.