| With the development of wireless communication, the demand of a amount of data file transmission and high-definition video services increased, the millimeter wave band 60GHz free license frequency band(57-64GHz) with the wide bandwidth of 7GHz attracting increasing attention. However, the millimeter wave band electromagnetic wave has serious oxygen absorption and path loss, so it is required that the antenna has wide bandwidth and high gain. So, the research and design of broadband and high gain antennas are theoretical significance and application value.Electromagnetic band gap structure mainly has two important characteristics: surface wave band gap (EBG) characteristics and in-phase reflection phase (AMC) characteristics. By using the surface wave band gap characteristics of EBG structure can be used to improve the gain characteristics of the antenna; by using the in-phase reflection phase characteristics of EBG can be low profile of reflector antennas; using EBG as cladding can improve gain and directivity of the antennas. In this paper, a new wide band gap UC-EBG structure is designed for the broadband and high gain antennas in the 60GHz millimeter wave communication system, and it is applied to millimeter wave antenna to improve the performance of the antenna.First of all, this paper takes the wide band gap EBG as the target,and six new types of EBG are designed based on the common high impedance surface EBG and UC-EBG structure. Including a new type of high impedance surface EBG (SS-ML-EBG) and five UC-EBGs(IS-UC-EBG, #S-UC-EBG, LS-UC-EBG, ILS-UC-EBG, CFL-UC-EBG).The methods of iteration, loop, surface slotting, increasing the equivalent inductance and so on are used to design and optimize EBG. Design of the EBGs are working in the vicinity of the 60GHz frequency, so the design of the EBG can be applied to the 60GHz high frequency microwave antenna.Secondly, this paper introduces a kind of U-shaped microstrip patch antenna, slot-cutting skill is used in the antenna to get third resonance points, which increases the total bandwidth of the antenna. In order to improve the gain performance of U-shaped slotted microstrip antenna,ILS-UC-EBGs proposed on the third chapter are placed around the antenna radiator,the analysis found that the antenna loading after EBG than the original 1.9GHz broadening the bandwidth of the antenna, the gain increases 2.85dBi.Finally, in order to satisfy the requirement of millimeter wave system for high gain performance, a dense dielectric patch antenna is designed, and one-dimensional EBG is used as the cladding to increase the gain and directivity of the antenna. In order to increase the bandwidth of the antenna, the double clad structure is adopted. The bandwidth of the double clad dense medium is increased by 0.85%, the gain is increased by 7.9dBi, and the gain is up to 14.6dBi.The above results provide a guide for design and analysis for the design of wide band gap UC-EBG structure in millimeter wave band,which provides a new idea for the application of EBG structure in antenna. |
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