Design of a Ka-band Wideband Multibeam Phased Array

【Objective】The world has entered the era of 5th Generation Mobile Communication Technology (5G) and satellite Internet, and the demand for communication speed and capacity in various fields has surged, while the application of traditional parabolic and narrowband planar phased array antenna systems is limited by factors such as bandwidth and beamforming. Based on the current trend of related industries and the application requirements of broadband multi-target, this paper studies the Ka-band wideband multi-beam solid-state phased array technology.【Methods】This paper theoretically establishes and derives a general vector mathematical simulation model of phased array antenna pattern, studies the subarray division, aperture effect, and crossing time of phased array antenna, and designs a broadband multibeam phased array system based on the combination of element-level electro-shift phase shift and sub-array stage optical-delay. The front-end single integrated subarray adopts the three-dimensional high-density heterogeneous tile integration scheme of different material substrates, which greatly improves the integration degree of the subarray. The sub-array post-stage adopts the Optical True Time Delay (OTTD) method based on optical switching, high-precision optical fiber delay line and wavelength division multiplexing to realize multi-channel delay and multi-beam synthesis of the sub-array stage.【Results】By integrating and testing the principle prototype of the Ka-band wideband multi-beam receiving phased array system, it is verified that the principle prototype overcomes the bandwidth limitation problems such as aperture crossing time and beam skew. The prototype can realize the wide-angle scanning of eight independent receiving beams in the Ka-band, and the maximum transmission data rate of each receiving beam can reach 1 500 Mbit/s.【Conclusion】The test results show that the system has the advantages of high integration, large bandwidth, and multiple independent beams. The research results will help promote the further development of wideband multi-beam solid-state phased array, and lay a theoretical and practical foundation for the subsequent engineering and productization of Ka-band wideband multi-target phased array.