| Multi-beam lens antenna,composed of dielectric lens and feed array,can form multiple beams in different directions.They have been widely used in the field of wireless communication and modern radar,with the advantages of high gain,small volume,low cost,and easy realization of wide-angle scanning.However,the scan coverage of the lens antenna is usually limited to 180° due to the shielding of the feed and the mounting structure.In this paper,the multi-beam lens antenna which can realize 360° scanning in horizontal plane is studied in detail.The main achievements are as follows:1.A multi-beam antenna based on a cylindrical lens which can realize 360° scanning in azimuth plane is introduced in this paper.Compared with the spherical lens,this multi-beam antenna has the advantages of simple structure and low cost.Firstly,the theoretical analysis on the feed position of the lens antenna is accomplished;then we choose the linear tapered slot antenna(LTSA)as the feed antenna,and analyze the influence of some parameters on the performance of LTSA using the full wave simulation software HFSS.A circle of LTSA antennas is placed at equal distance around the lens to form a feed array,utilizing the circular symmetry of a cylindrical lens,and two parallel metal plates are loaded on the upper and lower ends of the cylindrical lens to improve the waveform in vertical plane.Beam scanning in azimuth plane can be achieved by switching among the TSA units.Finally,the CST-MWS is used to simulate and optimize the cylindrical dielectric lens antenna at 24GHz,which can realize a 360° beam coverage in azimuth plane.The gain of the proposed antenna can reach up to 15.2dB.2.A millimeter-wave multi-beam antenna based on a hemispherical lens which can realize 360° scanning in azimuth plane is proposed in this paper.Based on the principle of mirror image,the problem caused by the shielding of the feed source and the mounting structure in omnidirectional scanning multi-beam antenna is thoroughly solved by the hemispherical lens.The structure of the antenna is simple and the beam is symmetrical,and the effective separation of the radiation area and the feed area is realized.A new type of planar dielectric rod feed antenna fed by a substrate integrated waveguide(SIW)is proposed,and the influence of the main parameters on the performance of the feed is analyzed by the analytical method.The full wave simulation software is used to analyze the optimum distance between the feed and the lens antenna,and the influence of the main parameters is analyzed.In order to verify the effectiveness of the antenna,a millimeter-wave(35GHz)hemispherical lens antenna with 36 simultaneous beams is designed.And the physical processing and testing are carried out.The measurement indicates that the beam consistency is very good,with the excellent performance,and the sidelobe level is kept below-15dB. |
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