Hybrid Wideband Staircase Filters in Rectangular Waveguide With Enhanced Out-of-Band Response

• Published in: IEEE transactions on microwave theory and techniques Vol. 69; no. 8; pp. 3783 - 3796
• Main Authors: Valencia Sullca, Joaquin F., Guglielmi, Marco, Cogollos, Santiago, Boria, Vicente E.
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.08.2021; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Aggressive space mapping (ASM); bandpass filters; Broadband; Couplings; Electromagnetic wave filters; hybrid (inductive and capacitive) irises; manifold connections; Microwave filters; Passband; Prototypes; Rectangular waveguides; Resonators; Selectivity; staircase configuration; Topology; Waveguide discontinuities; Wideband; wideband response
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2021.3076061

The objective of this article is to describe the design of a new family of wideband filters in a rectangular waveguide based on hybrid couplings and a staircase configuration. The use of <inline-formula> <tex-math notation="LaTeX">E </tex-math></inline-formula>-plane <inline-formula> <tex-math notation="LaTeX">T </tex-math></inline-formula>-junctions and <inline-formula> <tex-math notation="LaTeX">E </tex-math></inline-formula>-plane folded structures is also discussed, in order to enhance the out-of-band response and the selectivity of the filter with respect to the current state of the art. The design of several hybrid filter prototypes is discussed in detail, including manufacturing sensitivity and high-power analysis. Finally, simulations and measurements for an eight-pole filter prototype are also compared, showing very good agreement, thereby fully validating both the design procedure and the new filter topology that we propose.