设计了一种涂覆石墨烯的混合型电介质纳米并行线波导。这种波导由两根圆柱形和一根椭圆柱形电介质纳米并行线组成。利用有限元方法对5个最低阶模式进行了分类，研究了工作波长、石墨烯的费米能和结构参数对5个最低阶模式的有效折射率实部、传播长度和品质因数的影响。结果表明：5个最低阶模式均可由圆柱形纳米线和椭圆柱形纳米线的低阶模合成。当调节工作波长和石墨烯的费米能时，5个模式的传输特性均可得到有效的调节。当结构参数变化时，前两个模式的传输特性变化比较显著，而其他三个模式的传输特性变化不明显。将所设计结构与由两根椭圆柱形和一根圆柱形电介质纳米并行线构成的波导相比较，发现所设计的结构具有更长的传播长度和更高的品质因数。该研究为涂覆石墨烯的混合型电介质纳米并行线波导的设计、制作和应用提供了参考。

In this paper, a graphene-coated hybrid dielectric nano-parallel wire waveguide is designed. This waveguide consists of two cylindrical and one elliptical cylindrical dielectric nano-parallel wires. The five lowest-order modes are classified, the effects of working wavelength, Fermi energy of graphene, and structural parameters on the real part of effective refractive index, propagation length, and quality factor of the five lowest-order modes are investigated by the finite element method. The results show that the five lowest-order modes can be synthesized from the low-order modes of cylindrical nanowires and elliptical cylindrical nanowires. The transmission characteristics of the five modes can be effectively adjusted when the operating wavelength and Fermi energy of the graphene are adjusted. When the structural parameters are changed, the transmission characteristics of the first two modes change significantly, while the transmission characteristics of the other three modes do not change significantly. Compared with a waveguide composed of two elliptical cylinders and a cylindrical dielectric nano-parallel wire, the waveguide structure designed in this paper has a longer propagation length and a higher figure of merit. The theoretical research in this work is helpful to the design, fabrication, and application of graphene coated hybrid dielectric nano-parallel wire waveguides.