Ka band active phase array antenna with digital beam former for the HAPS systems

HAPS(high altitude platform station) system have many attractive points for the next generation communication systems, focused on high data rate multimedia services. HAPS would be located around 20km above sea level and this altitude is very low when it is compared with satellite communication systems, even it is LEO systems. So HAPS systems could have enough link margin. In this paper, Ka band prototype active phase array antenna(APAA), including 19 channels with 7 beams controlled by means of digital beam former(DBF) is designed, we conclude that the APAA system based on the DBF technology is appropriate for the application in HAPS payload because DBF can achieve better performance than analog beam former.