TY - JOUR
T1 - Metagratings for Perfect Mode Conversion in Rectangular Waveguides
T2 - Theory and Experiment
AU - Killamsetty, Vinay Kumar
AU - Epstein, Ariel
N1 - Publisher Copyright: © 2021 American Physical Society.
PY - 2021/7
Y1 - 2021/7
N2 - We present a complete design scheme, from theoretical formulation to experimental validation, exploiting the versatility of metagratings (MGs) for designing a rectangular waveguide (RWG) TE10-TE20 mode converter (MC). MG devices, formed by sparse periodically positioned polarizable particles (meta-atoms), were mostly used to date for beam manipulation applications. In this paper, we show that the appealing diffraction engineering features of the MGs in such typical free-space periodic scenarios can be utilized to efficiently mould fields inside WGs. In particular, we derive an analytical model allowing harnessing of the MG concept for realization of perfect mode conversion in RWGs. Conveniently, the formalism considers a printed-circuit-board MG terminating the RWG, operating as a reflect-mode MC. Following the typical MG synthesis approach, the model directly ties the meta-atom position and geometry with the modal reflection coefficients, enabling resolution of the detailed fabrication-ready design by enforcement of the functionality constraints: elimination of the fundamental TE10 reflection and power conservation (passive lossless MG). This reliable semianalytical scheme, verified via full-wave simulations and laboratory measurements, establishes a simple and efficient alternative to common RWG MCs, typically requiring challenging deformation of the WG designed through time-consuming full-wave optimization. In addition, it highlights the immense potential MGs encompass for a wide variety of applications beyond beam manipulation.
AB - We present a complete design scheme, from theoretical formulation to experimental validation, exploiting the versatility of metagratings (MGs) for designing a rectangular waveguide (RWG) TE10-TE20 mode converter (MC). MG devices, formed by sparse periodically positioned polarizable particles (meta-atoms), were mostly used to date for beam manipulation applications. In this paper, we show that the appealing diffraction engineering features of the MGs in such typical free-space periodic scenarios can be utilized to efficiently mould fields inside WGs. In particular, we derive an analytical model allowing harnessing of the MG concept for realization of perfect mode conversion in RWGs. Conveniently, the formalism considers a printed-circuit-board MG terminating the RWG, operating as a reflect-mode MC. Following the typical MG synthesis approach, the model directly ties the meta-atom position and geometry with the modal reflection coefficients, enabling resolution of the detailed fabrication-ready design by enforcement of the functionality constraints: elimination of the fundamental TE10 reflection and power conservation (passive lossless MG). This reliable semianalytical scheme, verified via full-wave simulations and laboratory measurements, establishes a simple and efficient alternative to common RWG MCs, typically requiring challenging deformation of the WG designed through time-consuming full-wave optimization. In addition, it highlights the immense potential MGs encompass for a wide variety of applications beyond beam manipulation.
UR - http://www.scopus.com/inward/record.url?scp=85110390815&partnerID=8YFLogxK
U2 - https://doi.org/10.1103/PhysRevApplied.16.014038
DO - https://doi.org/10.1103/PhysRevApplied.16.014038
M3 - مقالة
SN - 2331-7019
VL - 16
JO - Physical Review Applied
JF - Physical Review Applied
IS - 1
M1 - 014038
ER -