Designing a plasmonic structure having high near field enhancement of incident field, large hot spot area, wideband resonance, and multiple resonance peaks are the key elements to obtain large electromagnetic field enhancement factor for various biosensors like surface-enhanced Raman scattering and Spasers. In this paper, we have proposed three different configurations of the bowtie nanoantenna represented as Single Bowtie Structure, Double Bowtie Structure (DBS), and Triple Bowtie Structure (TBS). Numerical simulations are performed with the characteristics of Nanoantenna and the analysis of the influence of the size parameter of the antennas along with the optimization of this parameter is performed to achieve the maximum near field enhancement. The result shows that TBS delivers the highest enhancement factor with a triple resonance peak. Whereas, in the second portion, the demonstrated results show the influence of the size on the enhancement of the incident field which further indicates, that as the size reduces the enhancement decreases. Furthermore, variations in the gap are simulated with four types having simple bowtie structure, reduced symmetry of DBS, reduced symmetry of TBS, and double reduced symmetry of TBS. The results significantly showed that type 4 configuration covers a wider wavelength with enhanced near electromagnetic field.

设计具有入射场高近场增强、大热点面积、宽带共振和多共振峰的等离子体结构是表面增强拉曼散射和Spasers等各种生物传感器获得大电磁场增强因子的关键要素。在本文中，我们提出了三种不同的蝴蝶结纳米天线配置，分别表示为单蝴蝶结结构、双蝴蝶结结构（DBS）和三重蝴蝶结结构（TBS）。针对纳米天线的特点进行数值模拟，分析天线尺寸参数的影响，并对该参数进行优化，以实现最大的近场增强。结果表明，TBS 提供最高的增强因子，具有三重共振峰。而在第二部分，演示的结果显示了尺寸对入射场增强的影响，这进一步表明，随着尺寸的减小，增强减小。此外，利用具有简单领结结构、DBS 的缩减对称性、TBS 的缩减对称性和 TBS 的双重缩减对称性的四种类型来模拟间隙的变化。结果显着表明，类型 4 配置覆盖更宽的波长，具有增强的近电磁场。TBS 的减少对称性和 TBS 的双重减少对称性。结果显着表明，类型 4 配置覆盖更宽的波长，具有增强的近电磁场。TBS 的减少对称性和 TBS 的双重减少对称性。结果显着表明，类型 4 配置覆盖更宽的波长，具有增强的近电磁场。