Transmitarray antenna based on parallel-plate transmission line with high efficiency and large gain bandwidth

Hossein Eskandari | Hamidreza Hassani

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=137401
Date :  2019/11/19
Publish in :    IET Microwaves, Antennas & Propagation
DOI :  https://doi.org/ 10.1049/iet-map.2019.0229
Link :  http://dx.doi.org/ 10.1049/iet-map.2019.0229
Keywords :Transmitarray antenna, high efficiency, wide bandwidth

Abstract :

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Abstract: A dual-polarised transmitarray antenna unit cell based on conventional parallel-plate with low loss and wide bandwidth is proposed. A conventional parallel-plate is developed into two new structures; the first structure consists of two sets of parallel-plates forming a four-wall transmission line, while in the second structure the plates of the first structure are replaced by sets of strips. To ease the fabrication, in both cases, the plates are etched on FR4 substrates. These two structures are evaluated as the unit cell of transmitarray antenna to improve the efficiency and gain bandwidth. There is a basic difference between these two unit cells: the first unit cell increases the phase velocity and the second unit cell reduces the phase velocity while passing through the unit cells. Therefore, the layout of the metal antenna plates designed based on the first unit cell becomes concave-like and the layout of the metal antenna plates designed based on the second unit cell becomes convex-like. The antenna designed based on the second unit cell results in higher efficiency as such this antenna is fabricated and measured. The measured results show that the antenna has a peak efficiency of 85.6 and 1 dB gain bandwidth of 22.6.