On the Design and Optimization of a 10 Port Directional Coupler at Microwave and Millimeter Wave Frequencies using Waveguide Technology

This paper presents the design, simulation, and optimization of a 10-port directional coupler, developed using rectangular waveguides. The purpose of this study is to enhance power distribution efficiency in advanced telecommunications and microwave systems, enabling them to be incorporated into more complex antenna feed systems. The design process begins with a focus on optimizing the electrical properties of the coupler, such as reducing return losses and transmission coefficients, using the CST Studio Suite software. Identification of optimal configurations within the frequency range of 14.50 to 22 GHz was enabled by performing iterative simulations using a WR-51 waveguide. The objective was to optimize to ensure maximum power transfer and minimum signal losses in the frequency range of 14.5 to 15.5 GHz. An initial version of the proposed 10-port coupler prototype was constructed using 3D printing with standard resin for cost-effective validation of form, fit, and function. This approach enabled quick design iterations and early flaw detection before final production.