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

Abstract

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 conductive 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 suitable 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 GHz and 1‐dB gain bandwidth of 30%.