Design of a power combiner based on a metallic waveguide array

Abstract

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.