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.