Multi-faced and multibeam DBF antenna for high altitude platforms station stages of antenna development

Advantages of the multi-beam antenna for Stratospheric Communication System (or HAPS) with digital beam forming (DBF) are demonstrated in comparison with analogue beam forming (ABF). To cover the service area from nadir to a circle of radius 55 km by 199 beams, the antenna system of seven flat active phased array antennas (APAA) is proposed. Due to high accuracy of amplitudes and phases in channels of the APAA with DBF, optimal cell forming as well as high spatial isolation between cells is obtained. Stages of antenna creating are considered. Results of the work at initial stages are presented too.