Open AccessVariable propagation constant directional coupler
Author(s) -
Guo J.,
Wu K.
Publication year - 2017
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
ISSN - 1350-911X
DOI - 10.1049/el.2017.0065
Subject(s) - power dividers and directional couplers , hybrid coupler , waveguide , propagation constant , variable (mathematics) , constant (computer programming) , optics , magic tee , coupling (piping) , rat race coupler , physics , materials science , computer science , mathematics , mathematical analysis , metallurgy , programming language
Variable propagation constant directional coupler is proposed and demonstrated. Compared with its conventional counterpart, the proposed coupler uses variable waveguide propagation constants as an extra degree of design freedom to achieve the required signal addition and cancellation. The operation principle is mathematically formulated and a step‐by‐step design methodology is presented. Two double‐layer two‐hole substrate integrated waveguide couplers: namely, one forward directional coupler and one backward directional coupler, are fabricated to validate the proposed concept. A coupling of −20 dB is achieved in both couplers and the maximum isolation of −47 and −52 dB are obtained by the forward and backward structures, respectively.