Lcd Phased Array Beam Steering Model And Algorithm Research

Laser phased array radar is new system radar combining with laser radar and phased array technology. It controls the beam by electrically addressing electrodes. Liquid crystal phased array (LCPA) technology is the most potential one of the beamsteering technologies for laser phased array radar. It can change the birefringence of liquid crystal by applying voltages, produce different phase delays when beam output the liquid crystal phase shifters, then perform the strengthening interference at specific direction and achieve the beamsteering. LCPA technology is derived from microwave phased array, however, it has many unique characteristics which is different with that.Thereby, its beamsteering model and the methods to observe high precise, high efficiency beam steering have been the key problems of LCPA technology.This dissertation is developed relied on a specific research project. The work of the thesis is shown below:1) Basis of LCPA is introduced. The optical anisotropy and electronic control of Liquid crystal are analyzed; the principle of liquid crystal phase shifters is researched, then the relation between phase delays and voltages imposed on electrodes of LCPA are presented when the beam are input.2) The general structure and design parameters of laser radar LCPA system are given; the technical difficulties of LCPA are analyzed, also the work process of the component is presented.3) Proposed the beam steering model of LCPA based on the microwave phased array. It can obtain more precise distributions of far field beam intensity and establish the fundation of LCPA.4) Proposed a beamsteering approach of LCPA based on a nonperiodic blazed grating is proposed; Compared with the one based on binary blazed grating, it can achieve more steering angles and realize continuous beamsteering of almost all the resolvable spots over the field of view and will not decrease diffraction efficiency without combining with other devices.5) Proposed three algorithms of obtaining beamsteering data on the basis of iteratively modifying the output phase stairs and applied voltages of LCPA. They can observe exact beamsteering data and the beamsteering with high precision and efficiency can be obtained.At last, the simulations are given to testify the algorithms and beamsteering models.