K波段高增益超材料微带天线的拓扑优化设计

超材料微带天线的设计通常依赖经验,其中超材料基元的设计多以尺寸优化和形状优化为主。研究了常规超材料对微带天线增益性能的影响,发现其对增益性能的提升效果有限。提出了一种基于遗传算法的高增益超材料微带天线拓扑优化设计方法,对超材料基元采用整体设计的方法,以天线增益最大化为设计目标,以覆铜贴片方格子的有无为设计变量,建立了K波段(24 GHz)超材料微带天线的拓扑优化模型。进而基于遗传算法的求解策略,获得了一种新颖的超材料微带天线构型。仿真结果表明优化后的超材料微带天线侧向辐射得以抑制,其最大增益提升到10.5 dB,与普通微带天线相比性能提升了35%。同时通过改变覆铜贴片格子的布置规模对优化设计结果的收敛性进行分析,分析结果显示创新构型超材料微带天线设计结果是收敛的,且10*10方格子规模下的创新构型制备性价比最高。最后研究了超材料基元单独设计与整体设计的天线工作频率匹配对比,对比结果证实了超材料基元采用整体设计对于超材料微带天线拓扑优化是非常必要的。

Topology Optimization of the Metamaterial Microstrip Antenna for High Gain within K-Band

Design of the metamaterial microstrip antennas usually relies on experience, and the designs of metamaterial cells are mostly about size or shape optimization. In this paper, the influence on the gain performance of a microstrip antenna from the conventional metamaterial is studied, and it is found that its effect on the gain performance is limited. Then a topology optimization design method of the metamaterial microstrip antenna for high gain is presented based on the genetic algorithm. The design of metamaterial cells adopts the global design method; and taking the antenna gain maximization as the design goal, the presence or absence of square copper patch lattices as the design variables, the topology optimization model of metamaterial microstrip antenna within K-band (24 GHz) is established. Furthermore, based on the genetic algorithm, a novel metamaterial microstrip antenna microstructure configurations is obtained, simulation results show that the lateral radiation of the optimized microstrip antenna is suppressed, and its maximum gain is increased to 10.5 dB, the improvement rate is 35% compared with the case of an ordinary antenna. At the same time, the convergence of the optimization design problem is analyzed through changing the layout sizes of square copper patch lattices. The results show that the creative configuration design of the metamaterial microstrip antenna is convergent, and the microstructure configuration for 10*10 lattice size is the most cost-effective. Finally, the matching comparison on working frequency of microstrip antenna is studied between the metamaterial cells separate design and the global design,the results confirm that the global design of the metamaterial cells is necessary for the topology optimization design of the metamaterial microstrip antenna.