矩形天线阵OAM波产生与优化

Generation and optimization of OAM waves based on rectangular array

电磁轨道角动量(orbital angular momentum,OAM)具有模值相互独立且正交的特性,能用于无线通信中提高频谱效率和通信容量,因而备受关注。针对基于矩形阵列的多输入多输出技术(multiple-input multiple-output,MIMO)不易与基于均匀圆形阵列的OAM复用相结合,以及高模态OAM波的大发散性与高衰减的问题,提出了一种基于大型矩形阵列生成OAM波的方法;为进一步优化矩形阵列的性能和降低复杂度,利用遗传算法实现了阵列稀疏化。仿真结果表明:能在不改变既有主动天线单元的前提下,高效生成OAM波;可将矩形阵列的总元素减少约25%,实现峰值旁瓣电平(peak side lobe level,PSLL)降低70%,稀疏后的信道容量与稀疏前非常逼近。该方法将有助于OAM在现有的MIMO与2D天线阵列中的应用。

Electromagnetic orbital angular momentum(OAM)has the characteristics of independent and orthogonal modulus.It can be used in wireless communication to improve spectral efficiency and communication capacity,so it has attracted much attention.Aiming at the problem that multiple input multiple output(MIMO)technology based on rectangular array is not easy to combine with OAM multiplexing based on uniform circular array,and the large divergence and high attenuation of high-mode OAM wave,a method of generating OAM wave based on large rectangular array is proposed.In order to further optimize the performance and reduce the complexity of rectangular array,genetic algorithm is used to realize array sparsity.The simulation results show that OAM wave can be generated efficiently without changing the existing active antenna elements.The total elements of the rectangular array can be reduced by about 25%,the peak side lobe level(PSLL)can be reduced by 70%,and the channel capacity after sparse is very close to that before sparse.This method will contribute to the application of OAM in existing MIMO and 2D antenna arrays.