Design Of Dual-frequency Planar Reflectarray Antenna

The planar reflectarray antenna combines the advantages of a parabolic antenna and a microstrip array antenna.Compared with a parabolic antenna,a planar reflectarray antenna replaces a "surface" with a "plane",and has the advantages of small size,low profile,and easy processing;Compared with microstrip array antennas,planar reflectarray antennas use air-feeding instead of complex feeder networks to reduce losses and improve antenna efficiency and gain.However,with the continuous development of modern communication technologies,not only the antennas are required to have low cost characteristics in civilian and commercial applications,but also the antennas are required to have good radiation performance in two or more frequency bands.Therefore,it is of great significance to actively carry out research on higher performance and low cost dual-frequency planar reflectarray antennas to meet the requirements of modern communication systems.The main work of this paper is as follows:1.The basic principle of planar reflectarray antenna,four phase shifting modes of typical array elements and analysis techniques of phase shift characteristics are introduced.The characteristics of the "Waveguide Approach","Master-Slave Boundary Approach" and "Simplified Waveguide Approach" are discussed in depth,and the phase shift curve of the microstrip reflection element is obtained by taking the square patch element as an example.The simulation results were compared.At the same time,the main indicators for measuring the performance of the planar reflectarray element and the principle of selecting the element spacing are elaborated.2.Aiming at the problem that the planar reflectarray antenna how to achieve normal operation and non-interference in both frequency bands,compared with the advantages and disadvantages of other design methods,a dual-frequency multi-layer planar reflectarray antenna based on frequency selective anti-reflection technology is designed.3.Aiming at realizing low-cost and achieving the performance of high-cost reflectarray antenna,a single-frequency high-gain planar reflectarray antenna based on hybrid element reflection surface technology is designed by changing the carrying mode of reflective surface and metal ground.4.Combined with the design idea of "frequency selective anti-reflection technology" and "hybrid element reflective surface technology",a dual-frequency high-gain planar reflective array antenna operating at 10.0GHz and 14.0GHz respectively was designed,which is low cost.In thecase of cost,the dual-frequency radiation performance has been greatly improved compared to the first edition.The dual-frequency beam directions of the antenna are:(0°,0°),the measured center frequency gains are: 22.1d B and 25.3d B,and the sidelobe suppression is lower than-15 d B.The simulation and the measured results are in good agreement,which verifies the good dual-frequency performance of the antenna.