Toward Ultracompact Multi-Materials Rectangular Waveguide Terminations

• Published in: IEEE transactions on microwave theory and techniques 2023-01, Vol.71 (1), p.12-21
• Main Authors: Zinkiewicz, Gautier, Chevalier, Alexis, Laurent, Paul, Benedicto, J., Maalouf, Azar, Laur, Vincent
• Format: Article
• Language: English
• Subjects: Additive manufacturing; Bandwidth; Dielectrics; electro-thermal device modeling; electromagnetic (EM) composite materials and measurements; Impedance; Maximum power; microwave absorbers; microwave measurements; passive components; Physics; Polylactic acid; power-handling capability (PHC); Programmable logic arrays; Rectangular waveguides; Superhigh frequencies; Three dimensional printing; Topology; Waveguide components
• ISSN: 0018-9480; 1557-9670
• DOI: 10.1109/TMTT.2022.3188318

A new multi-materials' compact topology, allowed by multi-materials 3-D-printing, is proposed to design microwave terminations in rectangular waveguide technology. The concept is based on a Salisbury-like resonant absorber constituted of a 3-D-printed polylactic acid (PLA) dielectric spacer and a lossy dielectric in the form of a pad whose dimensions allow controlling the frequency of maximum absorption. The flange of the termination is also printed with a lossy dielectric to achieve a compact and low-weight component that can be directly connected to a standard metallic waveguide. The concept has been validated experimentally in K-band (18-26 GHz) and X-band (8-12 GHz) with relative bandwidths (RBWs) around 20% for both frequency bands. These components demonstrate a quite stable temperature behavior. The power-handling capability (PHC) has been investigated through simulations and experiments. It was demonstrated that the maximum power than can support the termination is around 4-5 times lower than a more standard and bulky termination made with the same materials.