The Research Of High Gain Antenna Based On Electromagnetic Metamaterials

Currently, the high gain microstrip antenna has the advantages of high directive planar, light weight and simple production technology, is attracting more and more people’s attention, high gain microstrip antenna can be widely used in microwave fields, such as RFID systems, wireless communication systems, near-field communications, satellite navigation, etc. For a single antenna, if you want to enhance its gain and directivity, then will face the loss of other electromagnetic parameters. With the proposed of artificial electromagnetic metamaterial, people can achieve negative index by controlling its structure. And then we can use the method of integrating the metamaterials unit and antenna reasonable, so that the antenna gain can be improved without changing the main structure of the antenna. Based on this idea, this paper identified the target, combination of different system requirements for the antenna, designed two different types of metamaterial antennas to meet different application needs,the two metamaterial antenna structure include an antenna unit, fed electricity networks and metamaterial periodic structure.The main frame of the article is as follows:The first two chapters expounds the basic antenna and negative refractive index metamaterials theory. In the third chapter, designed a microstrip antenna based on a periodic structure fishnet metamaterial unit’s, the part of antenna through the use of an array of structures to increase the gain, the feed network is consisted of a Wilkinson power divider and two T-junctions parts.The antenna structure is simple, good radiation performance. Metamaterial unit using fishnets structure, the intermediate part of the medium version using FR4 board.Then the metamaterial unit combination into a periodic structure and loaded in the main radiation direction of the antenna. This section metamaterial antenna working in the 9.2GHz-9.6GHz band, and in the workband, its gain directivity compared to a single antenna have significantly increased.In the fourthchapter, I designed an UWB Vivaldi antenna structure which based on periodic metamaterial unit. Based on the performance analysis of the end-fire antenna, through the loading opening of a slot line of the outer edges of the metal copper, and the SRR type structure metamaterial unit, compared to the pure antenna structure, in the 8GHz-18 GHz band, the direction of the antenna have been significantly improved.In the fifth chapter, fabricating the two designed metamaterial antennas, and tested its various properties, such as gain, directional maps.