1. Synthesis and Measurement of DBE Exceptional Points in Substrate-Integrated Waveguides.
- Author
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Zheng, Tianyu, Casaletti, Massimiliano, Abdelshafy, Ahmed F., Capolino, Filippo, Ren, Zhuoxiang, and Valerio, Guido
- Subjects
- *
SLOW wave structures , *TRANSMISSION line matrix methods , *UNIT cell , *DISPERSION relations - Abstract
This article proposes a method to engineer degenerate band-edge conditions in periodic substrate-integrated waveguides (SIWs). A degenerate band edge (DBE) is a fourth-order exceptional point originating from the coupling of four Floquet–Bloch modes; it leads to a dispersion relation flatter than a regular band edge (RBE) and is suitable to design slow wave structures and high $Q$ -factor resonators. Design guidelines to achieve a DBE point are given based on Bloch analyses of unit cells. An oblique line of vias in SIW is proposed to form a suitable modal coupling between adjacent waveguides enabling a degenerate band-edge condition. The effect of losses and the robustness to parameter variations are discussed by means of rigorous Bloch analyses. A unit cell showing the best behavior concerning the losses and geometric tolerances is selected and prototypes of finite-length resonators are realized. Measurements validate simulated results and confirm the typical $N^{5}$ scaling of the loaded $Q$ -factor to the number of cells $N$ of the resonator. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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