Design Of Cylindrical Conformal Phased Array Antenna Based On Liquid Crystal Material

With the development of electronic information technology,the scanning range of traditional planar phased array antenna is difficult to meet the requirements.Conformal design is one of the effective ways to improve beam scanning range,and it is one of the important directions of phased array antenna design and development in the future.In addition,the conformal phased array antenna can be fitted to the carrier surface to reduce the impact on the aerodynamic performance of the carrier.It has important research significance in airborne,missile borne and other fields.In this thesis,the most practical cylindrical structure in engineering is used as the carrier,and the conformal phased array antenna is designed based on liquid crystal materials,so as to make up for the problem of insufficient scanning range of planar phased array antenna,and provide a new technical implementation way for the design of conformal phased array antenna.The main research contents are summarized as follows:1.The beam control principle of phased array antenna and the microwave physical properties of liquid crystal are studied.The design method of phase shifter based on the liquid crystal is analyzed.Due to the fluidity of liquid crystal material,it is less affected by the carrier during conformal,which is suitable for conformal design.2.The 5×5 cylindrical conformal liquid crystal phased array antenna is designed based on rectangular microstrip patch antenna.The center frequency of the antenna array is 16 GHz,the beam scanning range is ±30° in the simulation,and the peak gain is 18 d Bi.The antenna array is fabricated and measured,and the performance of the designed antenna array is preliminarily verified.3.The circularly polarized microstrip patch antenna element is designed by slot perturbation,and the cylindrical conformal linear phased array antenna is designed.The center frequency of the antenna array is 15 GHz.The performance changes of antenna array with different cylinder radius and different array element angle are analyzed by simulation.The simulation results show that the conformal array antenna can achieve omni-directional beam coverage along the cylindrical circumference by properly adjusting the included angle and phase difference between adjacent array elements.