High Gain And Directivity Grounded-penetrating Radar System Loaded With Metamaterial

Metamaterials are materials typically engineered with novel or artificial structures to produce electromagnetic properties that are unusual or difficult to obtain in nature. Because of their promise to provide engineerable permittivity, permeability, and index of refraction, metamaterials have drawn broad interest and have led to possible utilization in many electromagnetic applications from the microwave to optical regime, especially for the radiated-wave devices. This paper presents a detailed review upon the most recent research efforts associated with metamaterial-based antennas.In this paper, two kinds of metamaterial-based are designed according to the theory of metamaterial and antenna, and the design of the antenna can be used in ground penetrating radar system. A bowtie antenna is designed. Its structure is simple and the cost is low, so it is widely used in ground penetrating radar system. Despite of its broad band characteristics, the designed antenna has a bad radiation pattern with dual radiation. In order to solve the problem of antenna radiation, a metal back cavity is put forward to change the antenna’s radiation pattern so that it can radiate to one side. While solving the bowtie antenna radiation pattern, but the directivity of the antenna needs to be improved. In order to solve the problem of antenna directivity, a zero refractive index is proposed, which is loaded on the antenna, to improve the directivity of the antenna and the antenna gain is increased by 1.725 dB.The traditional Vivaldi antenna with ultra-wideband characteristics. A zero-index metamaterial (ZIM) structure is presented for the gain and directivity reinforcement of the Vivaldi antenna. We embed ZIM cells in the original Vivaldi antenna to improve the gain and directivity of the antenna, making the overall structure compact. The simulated results indicate that the gain of the Vivaldi antenna loaded with the ZIM cells has been enhanced by 0.9 dB-2.48 dB, and the half-power beam width has been decreased by least 10 degree, compared with original Vivaldi antenna. The measured results are well consistent with the simulated onesThe main innovative points of this paper are:the designed metamaterials with special nature is introduced to improve the gain and directivity of antennas.