Research On Miniaturized Low Profile And High Gain Lens Antenna

As a kind of lens antenna,the transmission array antenna consists of a feed and a planar array with a large number of transmission units.It has the advantages of small volume,high gain,and flexible beam controlling,,which becomes a new choice in application for high-gain antennas.In this paper,the analysis of unit structure is put forward,based on which a transmission array antenna is realized with the low profile and high gain features.The main contents and innovations of this paper are organized as follows:(1)A three-layer double-ring resonant unit structure with a center frequency of 5.8 GHz is proposed,rather than the conventional way by varying the size,and the phase shift range is greater than 360°with good transmission coefficients through parameter optimization.Using this unit,a 14×14 linearly polarized transmission array antenna with a pyramid cone as the feed is designed.The antenna operates from 5.6 GHz to 6.4 GHz,and the gain can reach 22.5 dB.The 1 dB gain bandwidth is about 14.5%.Thereafter the oblique incidence focal length ratio characteristics of the transmission array is analyzed.The proposed transmission array antenna is processed and measured.The measured results are in good agreement with the simulation results.The measured maximum gain can reach 22.24dB,which realizes the design of high-gain and high-directional linearly polarized transmission array antenna.(2)An angle-rotating single-layer multi-resonant circularly polarized unit is proposed.The thickness of the unit section is only 1 mm,which has obvious advantages of low profile.Based on the results of the unit,a 14×14 circularly polarized transmission array antenna with a cone-shaped horn as the feed is designed.The gain can reach up to 20.1 dB,which realizes the characteristics of low profile and high gain,and then studies on the circularly polarized transmission array is presented.The focal length ratio characteristics and oblique incidence characteristics were investigated.On this basis,the machining measurement is carried out,and the simulation and the measured results are in good agreement.The design of the circularly polarized transmission array antenna with low profile,high gain and single-layer multi-resonance structure is realized.(3)According to the theory of array antenna,a new idea of using hybrid unit to optimize the transmission array antenna is proposed.By calculating the incident angle of the incoming wave of each unit position of the array,the area of the front is divided,and the unit type is determined by the difference of the different unit patterns and the incident angle of the incoming wave at different positions,and the mixed unit group is tentatively introduced.The method of array.Finally,a 14×14 array antenna is formed by using a hybrid array unit,and the simulation results are compared with the results of a single unit transmission array antenna.It is found that the gain of the hybrid unit transmission array antenna is improved by about 3 dB,and the maximum is up to 23.5 dB.At 22.4 dB,the back radiation is significantly reduced,indicating the theoretical correctness of the hybrid unit array.