A 3 × 1 power combiner based on a metallic waveguide array is proposed. The waveguide array is composed of five waveguides. The supermode theory of surface plasmon polaritons (SPPs) is applied to analyse the field distributions in the metallic waveguide array. The coefficient of excited supermodes can be determined quantitatively by the input fields. In order to get a solution of power convergences, we block the 2nd and the 4th waveguides at the entrance and the other waveguides are open. By employing the SPPs supermode theory, the appropriate input fields are chosen for power combining. The field energy from the 1st, the 3rd and the 5th waveguides are combined to the 3rd waveguide at z = 0.61 μm in the metallic waveguide array and a 3 × 1 power combiner is obtained. By a similar method, an n × 1 power combiner can be obtained. The theoretical results are verified by the finite-difference time-domain method.

提出了一种基于金属波导阵列的3×1功率合成器。波导阵列由五个波导组成。应用表面等离子体激元极化子（SPPs）的超模理论分析了金属波导阵列中的场分布。可以通过输入字段定量确定激发的超模的系数。为了获得功率收敛的解决方案，我们在入口处阻塞了第二个和第四个波导，其他的波导是敞开的。通过采用SPP超模理论，可以选择适当的输入场进行功率组合。在金属波导阵列中，来自第一，第三和第五波导的场能在z  = 0.61μm处组合到第三波导，并获得3×1功率组合器。用类似的方法，一个Ñ 可获得×1个功率合成器。通过时域有限差分法验证了理论结果。