Research And Design Of Ku-band Broadband Dual-polarized Flat Panel Array Antenna

Dual-polarized antennas are widely used in the field of satellite communications because of their adjustable polarization and extended channel capacity.At this stage,high-capacity satellite communication systems require antennas to be lightweight,portable,and low profile,and flat panel array antennas have received great attention.In this paper,based on the satellite communication system,the Ku-band broadband dual-polarized planar array antenna is studied.A high-efficiency,high-gain,wide-band,high-port isolation double-polarized flat array antenna is designed and developed.Firstly,according to the requirements of actual use environment,three different configurations of Ku-band dual-polarized antenna elements,microstrip patch antenna units,horn antenna units and microstrip waveguide antenna units are designed.These three antenna elements can be applied to the project according to actual requirements.Secondly,this paper designs a high-bandwidth coaxial waveguide converter,which is transformed into a rectangular waveguide by a ridge waveguide structure.The symmetrical structure effectively suppresses higher-order modes.The measured results show that the designed coaxial waveguide converter has low loss characteristics.Then,for the Ku-band high-gain antenna array requirements,the horn antenna is used for arraying,and the main electrical parameters of the horn antenna unit are analyzed.It is proposed to load a metal grid of a certain thickness to effectively reduce the grating lobe level.A kind of equal-amplitude waveguide power splitter is designed to perform physical processing on the 4×4 array antenna.The assembly test results show that the port isolation is better than 40 dB,the standing wave is less than 2 in the working frequency band,and the antenna gain is higher than 23.9dBi.Finally,the 8×8 array antenna is subjected to down-grid processing and down-valve processing,and the antenna size is 284 mm×284 mm×65 mm.The results show that the side-lobe level of the receiving port is-13 dB,the gain is greater than 29.3dBi,and the grating-gate level normalization value is around-20 dB.For the transmitting port,the side-lobe level is about-16 dB and the gain is at least 33.1dBi.The grating gate level is normalized to-22 dB,and the total antenna efficiency is higher than 66%.