A tunable splitter upon a planar hyperbolic metamaterial

Autor: M.А. Miliaiev, S.V. Nedukh, S.I. Tarapov
Jazyk: English<br />Russian<br />Ukrainian
Rok vydání: 2020
Předmět:
Zdroj: Радиофизика и электроника, Vol 25, Iss 1, Pp 80-85 (2020)
Druh dokumentu: article
ISSN: 1028-821X
2415-3400
DOI: 10.15407/rej2020.01.080
Popis: Subject and Purpose. The paper presents the development and testing of a microwave splitter based on a planar hyperbolic metamaterial with a structural defect. The planar hyperbolic metamaterial is so constructed that a propagating electromagnetic (EM) wave is channeled in a certain direction depending on the metamaterial parameters. The wave splitting is possible where a part of the incident wave is reflected from a defect created inside the metamaterial. As the defect spatial orientation relative to the incident EM wave changes, the propagation direction of the reflected EM wave also changes. By this means the wave propagation control can be implemented in the considered splitter. Methods and Methodology. A defect in a planar hyperbolic metamaterial is created using the circuit theory that relates the material parameters to the equivalent unit-cell capacitances and inductances which, in turn, depend on the parameters of the microstrip line and capacitors. Thus, a change in any parameter of the circuit inside the unit cell changes its material parameters and makes a defect cell. In this work, a defect is created by changing the capacitance of the capacitors in a given set of elementary cells of a planar hyperbolic metamaterial, controlling thereby the size of the defect and its spatial location relative to the propagating wave. The numerical model of EM wave propagation inside a planar hyperbolic metamaterial with a defect is validated by experiment. In it, the field distribution over the metamaterial surface is obtained using the active probe method in the three cases: a defect-free metamaterial and two variants of defect orientation. To insert the electronic control, it is proposed to replace the elementary cell capacitors with varactors. Results. The obtained field distributions show that the defect partially reflects the incident EM wave channelized in the planar hyperbolic metamaterial. As the defect location angle changes, the wave reflection angle also changes. To make a defect unit cell, it will only suffice to change its capacity by 20% from the original, which is quite feasible in modern varactors. Conclusion. The performed studies have shown that the considered planar hyperbolic metamaterial with a structural defect is good for creating tunable electromagnetic wave splitters.
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