The Research And Application On Technology Of Flat Lens Antenna

With the rapid development of microwave technology,the antenna is proposed more strict requirements in modern radar and communication system.And the antenna of broadband,high-gain and miniaturization has become an obvious trend with great concern from researchers.In the recent years,lens antenna attracts on more and more attention due to its innate characteristics,like low profile,high gain and simple principle.In this paper,we keep eyes on the design and application of the flat lens antenna.On one hand,we offer an obvious way to design high gain lens antenna.On the other hand,we also manage to devise a beam forming lens antenna.Besides the similar principle of the lens antenna,the reflectarray is widely applied in many fields because of its low insertion loss characteristics.Meanwhile,comparing to the lens antenna,the reflectarray antenna is easier to design without regard to insertion loss.Therefore,in this paper,we offer a way to design reflectarray antennas as the foundation of lens antenna.The researches will be studied as follow.First of all,this paper briefly introduces the background of the lens antenna and the reflectarray antenna and some methods of beam-forming.In addition,as the foundation the solving mentioned problems,it also describes the geometric optics theory(GO)in the design of lens antenna and the phase compensation theory.Secondly,a new single-layer microstrip multi-resonance conformal loop element(MRCL)is proposed to design a printed beam deflector array.By utilizing variable parameters of the MRCL element,a nearly progressive phase-shift ranging more than 900°is achieved for deflecting wave within a wide band.It is important that a small MRCL element can be flexibly used to generate a 360°phase shift,which decreases the cell period between the neighboring elements.An X-band plane wave beam deflector array is designed by using this MRCL element.In addition,this paper also introduces a kind of genetic algorithm to increase the gain of reflectarray using Python and HFSS API.Thirdly,this paper researches an H-horn lens antenna with planar dielectric transmitarray.By adjusting the insertion phase of the antenna's aperture,a dielectric array lens with different dielectric blocks is designed.Then,the H-horn antenna which is assembled with lens realizes a kind of pencil beam in the far-field.And its 3d B-bandwidth of main-beam changes from 70°to 5.1°.Furthermore,in order to improve the return loss of lens antenna,two matching dielectric layers are placed on both sides of the lens.Finally,according to the above theories,a planar lens antenna with ISO beam is designed by using the generalized refractive index theory and controlled ray theory.Then we offer a multi-layer triangular patch structure to instead of a dielectric lens array.This structure offers enough phase range with low insertion loss.The new lens antenna achieved ISO beam between-30°to 30°.