Research On The Sparse Array Antenna Based On The Unitary Matrix Beam Method

The sparse array antenna is designed to use as few elements as possible to approach the performance of the uniform spacing array antenna by optimizing array element excitations and positions.Compared with the uniform spacing array antenna,the sparse array antenna has the smaller array elements and the larger elements spacing.Therefore,it has obvious advantages in reducing the complexity of the system and restraining the mutual coupling effect.The technology of sparse array antenna synthesis discussed in this paper is mainly to achieve the desired radiation pattern characteristics using sparse array under the condition of scanning angle and working frequency.In this dissertation,the optimal design of linear array antenna and planar array antenna is carried out by using the unitary matrix pencil method and its extention methods.The main work and contribution include the following several aspects:Firstly,the basic theory of matrix pencil method are introduced,and then the optimization antenna array model is given.The matrix pencil method is not effective in asymmetric beam forming.For this reason,the unitary matrix pencil method and its expansive methods are proposed.This method can greatly reduce the computational complexity while achieving high precision.In the third chapter,the principle of the unitary matrix pencil method is introduced and applied to the synthesis of the shaped beam pattern.Base on that,this method is used for multi-beam pattern synthesis.By sharing the same sparse array element position,different scanning beam is realized by changing the array element excitations.In the fourth chapter,the extended unitary matrix method is proposed for the synthesis of wideband sparse array.In a wide band,we can use sparse array to achieve frequency-invariant(FI)patterns.Then,this method is used for wideband multi-beam pattern synthesis.By sharing the same sparse array element positions,the wideband multi-beam scanning is realized by changing the array element excitations corresponding to different beams of different frequency points.In the fifth chapter,the 2-D unitary matrix pencil method is proposed for pattern synthesis of planar arrays.The key point of this method is to solve two dimensional poles and get the correct pairs.On this basis,this method is used for multi-beam pattern synthesis of planar arrays to realize multi-beam scanning.