Enhancing the Performance of Waveguide Filters Using Additive Manufacturing

This paper describes the development of resonator and coupling architectures that enhance the insertion loss and far out of band rejection of single-mode waveguide filters. The inherent geometrical freedom of 3-D additive manufacturing techniques is exploited to realize complex geometries monolithically. It also has the added benefit of reduced manufacturing lead time. Resonator and coupling structures using complex geometries are introduced and examples of manufactured direct-coupled-cavity filters are given. Analysis and measurements show excellent agreement. The suitability of the manufacturing process for standard and complex geometries is discussed.