Research And Design On The Patch Antennas Based On Metasurface

Experienced 130 years of development history, the categories of antennas have been maturing and growth of different types of antennas has played a pivotal role in various fields. Nowadays, the metamaterials were recognized as the hottest research topics in the electromagnetism,one of the most important and most promising engineering is the design of the antenna based on metamaterials. Since the material properties of metamaterials beyond the natural materials, which has brought new ideas for the development of the antenna, breaking many of the rules of the convention antenna design,the antenna structure design more flexible and diverse, the performance indicators are getting much higher. As the one of the most promising topic in metamaterials, the metasurfaces also shows great potentiality on antenna design. This paper designed two high-performance antennas based on metasurfaces, and for its the following research:In this paper, the uniform and gradient metasurface are applied to the design of wearable antenna and high-gain antenna, respectively. Wearable antenna requires a lower specific absorption rate (SAR), often need to add a back cavity behind the antenna, and the traditional back cavity needs to maintain a half wavelength distance with the feed antenna, thus the antenna profile will be too large. The uniform metasurface designed in this paper has a specific impedance characteristics,can be loaded directly behind the proposed patch antenna, reduce the profile below the one-tenth of the wavelength, which meet the requirements of wearable antenna. The antenna obtained 5.06?5.27 GHz and 5.68?5.84 GHz two operating band by loading the proposed metasurface,the SAR is also reduced to 0.1 W / kg below additionally, far below the minimum safety standards.In this paper, an electromagnetic waves fusion type metasurface is proposed to replace the parabolic reflector in traditional parabolic antenna by using the anomalous reflection phenomenon. The patch antenna is placed at front of the metasurface as a feed source, then the quasi-spherical wave emitted by the source is reflected and transformed to plane wave, this process will increase the antenna's gain of 6.5 dB to 20.3 dB, the beam width of the antenra has been decreased from 85.9° to 13°.Compared to the conventional parabolic shaped reflecting surface, the proposed gradient metasurface is easier to manufacture, transport and packaging, it may be mounted flush on a surface of a building or a ship, or a vehicle body made conformal, it has broad applications in the defense, aerospace and other fields.