In this paper, a shape optimization method for Multiple-Input Multiple-Output (MIMO) antenna-array with curved-groove defect ground structure (DGS) is proposed to improve the decoupling performances and maintain the radiation performances of array. The curved-groove DGS is depicted by the irregular shaped neutral-line and the neutral-line displacement shifted along the positive and negative y-axis directions. The curve shape function of the neutral-line is constructed and expressed as a trigonometric series. Thus, the factors corresponding to the trigonometric function expansion are used as the shape description parameters. The proposed method is to achieve the desired array performances by optimizing the shape description parameters of the curved-groove DGS. The parametric modelling is established based on the relationships between the performances and the shape description parameters, and the optimization problem is effectively solved by GA. A typical numerical example, i.e., a 2 × 1 MIMO array (36.9 × 24 × 1.6 mm³), verifies the effectiveness of the proposed method. The results show that, compared with non-DGS and the linear-groove DGS, the optimized curved-groove DGS can effectively suppress the mutual coupling of 37.92 dB and 21.73 dB, respectively, while ensuring that the array has the excellent performances and covers the predetermined WLAN frequency range (5.725 GHz ~ 5.825 GHz).

本文提出了一种具有弯曲凹槽缺陷接地结构(DGS)的多输入多输出(MIMO)天线阵列的形状优化方法，以提高阵列的解耦性能并保持阵列的辐射性能。曲线槽 DGS 由不规则形状的中性线和沿正负y偏移的中性线位移表示- 轴方向。中性线的曲线形状函数被构造并表示为三角级数。因此，三角函数展开对应的因子被用作形状描述参数。所提出的方法是通过优化弯曲凹槽 DGS 的形状描述参数来实现所需的阵列性能。基于性能与形状描述参数之间的关系建立参数化建模，通过遗传算法有效地解决了优化问题。一个典型的数值例子，即一个 2 × 1 MIMO 阵列（36.9 × 24 × 1.6 mm ³)，验证了所提出方法的有效性。结果表明，与非 DGS 和线性槽 DGS 相比，优化后的曲线槽 DGS 可以分别有效抑制 37.92 dB 和 21.73 dB 的互耦合，同时确保阵列具有优异的性能并覆盖预定的 WLAN 频率范围（5.725 GHz ~ 5.825 GHz）。