Achieving Time-invariant Spatial Focusing By FDA

Frequency Diverse Array(refered to as FDA)is a new type of narrowband array.Compared to traditional arrays,the biggest feature of this array is that the operating frequencies between the array elements are different and there are certain differences,this allows the array to have multi-correlation properties(simultaneous time and space related characteristics)usually not found in traditional arrays and can provide new solutions in some application fields,so the array has attracted a large number of researchers to study for it.In the field of Wireless Power Transmission,there has been a lot of research on the application of arrays for Wireless Power Transmission to specified points and it has a certain research basis.However,the traditional arrays usually do not have distance-related characteristics,the efficiency of wireless energy transmission is often low and the stability is not high.Because of multi-correlation properties of FDA,it is able to achieve fixed-point focus of space,so,the research for it is very important.In this paper,the focusing characteristics of FDA are studied,intelligent frequency optimization algorithm is used to optimize the relevant frequency parameters to realize the Wireless Power Transmission of the array and it is verified in the near-field by CST lastly.The following five parts are mainly included in this paper:(1)Expounding the FDA's domestic and international research trends,background and significance;introducing the basic principles of FDA and the intelligent optimization algorithm.(2)Single-point focusing in far-field is achieved through FDA,the limits of focus position and the range of focusing parameters are calculated.By setting the FDA operating frequency to a time-varying function,the singal-point focusing in space with good focusing performance is realized by optimizing the frequency parameters with genetic algotithm.(3)The multi-point sequential focusing and multi-point simultaneous focusing are achieved by FDA.On the basis of single-point focusing,multi-point focusing of spatial far field is realized by performing fixed-point focusing optimization in different time periods;multi-point simultaneous focusing of spatial far field is realized by combining the parameter index of singal-point focusing and multi-point focusing,adding special target parameters.(4)The two-dimensional FDA is used to realize Wireless Power Transmission in the near-field specified point in free space.the genetic algorithm is used to optimize the operating frequency and weight by setting them as parameters,the spatial energy of the rectangular array and the circle array is realized.The characteristics of rectangular array's and circle array's focus are discussed,correctness of the optimization of rectangular array is verified by using CST.(5)Summarizing the research in this paper and proposing the next research direction,the prospects for the future development of the FDA is outlooked.