Reasearch On Beam Reconfigurable Reflectarray Antenna Based On PIN Diodes

The planar reflectarray antenna is an antenna array composed of patch elements with phase shifting function to realize the deflection of the reflected beam as required.It has the characteristics of easy processing,low profile and good conformal shape,and is widely used in satellite communications,radar aerospace and other fields.With the rapid development of aviation and electronic technology,the new requirements such as multi-function,multi-beam,and reconfigurability for the reflectarray antenna are further put forward.Therefore,it is of great significance to actively carry out the research on beam reconfigurable reflectarray antennas on the basis of the research on planar reflectarray antennas to meet the needs of modern wireless communication systems.In this thesis,the planar reflectarray antenna working in Ku-band and the beam reconfigurable dual-frequency reflectarray antenna based on PIN diodes are studied,and the main works are shown as follows:1.Aiming at the needs of modern airborne communication,based on the working principle of phase compensation of the variable-size element in the traditional reflectarray antenna,a cross double rings element operating at 13 GHz is designed.The element has the characteristics of simple structure,wide operating frequency,large phase shift range and relatively smooth phase shift curve.A planar reflectarray antenna with beam radiation direction of(30°,90°)is designed using the cross double rings element,including a total of 400 cross double rings elements.The measured results show that the radiation direction of the reflected beam of the proposed planar reflectarray antenna is in good agreement with the simulated results and has good directivity,the gain is 22.98 d Bi,the half-power beam width is 12.7°,and the side lobe level is low.It has good radiation performance in Ku band.2.Aiming at the multi-function,multi-beam,and reconfigurable requirements of reflectarray antenna,by loading a PIN diode on the reflectarray element,a reflectarray element operating at 3.82 GHz and 4.52 GHz with a phase difference of 180° between PIN diode conduction and cutoff is obtained.Based on the reflectarray element,a 12×12 beam reconfigurable dual-frequency reflectarray antenna is proposed by introducing the principle of array coding and digitally quantizing the compensation phase.The simulated and measured results show that the reflectarray antenna can achieve ±45° beam scanning at 3.82 GHz and 4.52 GHz.The measured gain is about 10 dBi at 3.82 GHz and about 13 dBi at 4.52 GHz.