High efficiency and gain bandwidth transmitarray antenna based on slow wave structure

Hamidreza Hassani | Hossein Eskandari

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URL :   http://research.shahed.ac.ir/WSR/WebPages/Report/PaperView.aspx?PaperID=159290
Date :  2021/11/14
Publish in :    International Journal of RF and Microwave Computer-Aided Engineering
DOI :  https://doi.org/10.1002/mmce.22856
Link :  http://dx.doi.org/10.1002/mmce.22856
Keywords :aperture efficiency, corrugated structure, gain bandwidth, slow wave structure, transmitarray antenna

Abstract :

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In this article, corrugated conductor plates with slow wave properties are used as slow wave unit cell structures to increase the aperture efficiency of the transmitarray antenna. The slow wave structure is composed of a simple con-ductive plate and a corrugated conductor plate facing each other. Two types of unit cells are considered for the design of the transmitarray antenna. In the first type, the spacing and height of the corrugated sections are constant, and only by changing the number of the corrugation the phase shift is created. In the second type, the distance of the corrugated sections and the number of the corrugation is constant, and only by varying the corrugated height, the phase shift is controlled. These slow wave structures can easily cover 360
and are also suit-able for large transmitarray. An array of such two types of slow wave unit cell structure is placed in front of the horn antenna and the aperture efficiency of the antenna is improved by the required phase correction. The transmitarray antenna based on the second type of the unit cell is fabricated and measurement results indicate that the transmitarray antenna has a maximum aperture efficiency of 89.4 at the frequency of 10.5 GHzand 1-dB gain bandwidth of 30.