Investigation On Coded Multi-beam Planar Antenna Array With Wide-Angle Coverage

The multi-beam antenna can cover a larger space area with a narrower beam and a higher gain,and can flexibly adjust the beam working state according to needs,which is widely used in satellite communications,radar detection and other aspects.The bit-coded antenna array is a new type of multi-beam antenna that has emerged in recent years and has attracted a lot of attention from the antenna academia.It loads the active devices on the antenna element,and quantifies the radiation phase of the antenna element by controlling its bias voltage,thereby realizing the multi-beam radiation function of the array.Compared with the traditional phased array technology,the bit-coded multi-beam technology has a simple structure and low cost,which is conducive to commercial massive applications.This paper proposes a new type of coded multi-beam planar array antenna,and studies its coding method and wide-angle multibeam forming theory.The differential evolution algorithm is used to synthesize the coded multibeam linear arrays and planar array antennas that work in the X-band,and the multi-beam radiation performance with wide-angle coverage is obtained.The main work of this paper is as follows:In the first chapter,the research background of the article is described,then summarizes the relevant domestic and foreign research status of the application of coded multi-beam antennas and intelligent optimization algorithms in antenna synthesis.In the second chapter,the synthesis method of the array antenna pattern based on binary differential evolution algorithm is proposed.Aiming at the desired beam direction and sidelobe level,this method can quickly synthesize the phase distribution of the array,so that the design of the multi-beam array can be realized by full-wave simulation.Due to the use of the technology that combines full-wave simulation and circuit optimization,and considering the mutual coupling factor between the elements,this method can not only save the time of the array antenna simulation design,but also have high accuracy.In the third chapter,a coded wide-angle coverage multi-beam linear array antenna is proposed and designed.First,a low-profile,wide-beam electromagnetic dipole antenna element and its coded feed structure are designed.By controlling the on and off states of the diode(PIN tube)in the feed structure of the antenna element,the feed with 2-bit phase control characteristics can be realized.Using the comprehensive method proposed in Chapter 2,a comprehensive design of a 1×16 linear array composed of the antenna elements is carried out,and achieving beam scanning with lower sidelobe levels in the range of ±50°.The experimental results verify the accuracy of the design.In the fourth chapter,a coded wide-angle coverage multi-beam planar array antenna is proposed and designed.Aiming at the application of massive MIMO,the antenna element designed in Chapter 3 is improved and an extra layer of bias circuit is designed for the bias circuit of the antenna to reduce the space occupied by the antenna elements.Using the improved antenna element,a two-dimensional 16×16 planar array antenna with beam scanning function is designed.Based on the optimization method proposed in Chapter 2,combined with the pattern shifting principle,a comprehensive design of the feed phase distribution of the twodimensional planar array is carried out.Using low-cost printed circuit board technology,the designed array antenna was produced and tested in the microwave anechoic chamber.Experimental results show that the developed two-dimensional planar array antenna can achieve arbitrary beam pointing within a range of ±40°,and all have good sidelobe levels.In the fifths chapter,investigations of this thesis are summarized and some suggestions on future works are given.