Research On Reconfigurable Antenna With Optical Control Pattern

With the development of the Internet,people have higher and higher requirements for wireless communication systems.As a key component of the wireless communication system,antennas are used more and more widely.Pattern reconfigurable antennas can reduce channel fading and multipath interference,improve the quality of signal transmission,which has attracted more and more attention.One of the realization methods of reconfigurable antennas is optically controlled microwave switch,which has the advantages of high electromagnetic isolation,fast switching response,no parasitic radiation and no DC bias circuit excitation.Therefore,the use of optically controlled microwave switch can effectively reduce the difficulty of antenna design and fabrication.Firstly,the research significance of optically controlled pattern reconfigurable antenna is introduced,and the development history of optically controlled microwave switch,reconfigurable antenna and optically controlled reconfigurable antenna is summarized respectively.A theoretical model conforming to the basic principle and structural characteristics of optically controlled microwave switch is established.Based on this model,the performance parameters of the switch are analyzed,which provides a basis for the simulation design and performance improvement of the switch.Secondly,based on the theoretical basis of the layered plasma model of the light-controlled microwave switch,an improved light-controlled microwave switch is proposed.Under the condition that the isolation of the switch remains unchanged,using the laser module to irradiate the photosensitive material on both sides can effectively reduce the insertion loss of the switch.This method needs to chisel a small cylinder on the dielectric substrate,the cylinder is located at the microstrip gap directly under the photosensitive material,so as to ensure the laser on both sides of the photosensitive material at the same time,which is the innovation of this article.Finally,two reconfigurable light-controlled pattern antennas are designed.The overall size of the first antenna is a circle with a radius of 31mm.It is a planar array composed of 4 slot units.Each slot unit can generate a directional radiation pattern.The light-controlled microwave switch on the slot unit is controlled by the laser to turn on and Disconnected,the antenna has 8 directional and multiple omnidirectional radiation patterns on the xoy plane.The antenna meets the wireless communication frequency band of 2.4GHz,the maximum directional gain is 2.9d Bi,and the omnidirectional gain is 1.37d Bi.The second antenna has an overall size of 55×55mm~2and works in the 5.65?5.95GHz frequency band.It consists of a main radiating element and four parasitic elements.The light-controlled microwave switch on the parasitic element is controlled by laser to turn on and off.The beam switches in nine different directions,and all the pattern gains are greater than 7d Bi.The two antennas were processed and tested in physical objects,and the test results showed that they were basically the same as the simulation.