Research And Fabrication Of Wireless Power Transmission Transmitting Antenna Based On Novel Electromagnetic Metamaterial

Compared with resonating or coupling wireless power transmission(WPT),microwave WPT method has the intrinsic advantage of long transmitting distance and high power density.High gain transmitting antenna is of great value for efficiency enhancement according to the Friss equation.However,conventional high gain antenna exhibits the disadvantage of non-planar profile,bulk volume,extra introduction of power divide circuit and incompatibility with other equipment.Thus,planar microstrip transmitting antenna with simple structure and easy fabrication becomes a good candidate in WPT.Electromagnetic metamaterials(MTM)witness wide-spread research attention in scientific community because of its exotic electromagnetic property and is also reported in the application of WPT,but usually restricted to the resonation or coupling WPT.In other words,the proposed method in microwave power transmission based on novel metamaterial structure is new.The main works are as follows:1.The research history and background of WPT were introduced and made comparison of some traditional methods applied in WPT.The advantages and disadvantages of some kinds of high gain transmitting antenna were presented and gave a review on the application of metamaterials in WPT.2.The detailed analysis of the achievement of negative permittivity and permeability for the MTM was studied and the MATLAB code for the retrieval method was shown in the paper.Transmission line model was adopted to interpret the MPA and simulation models were created in HFSS.3.We give a deep analysis of the origin of single left-handed frequency band for the conventional parallel incidence octagonal MTM structures,based on the existing octagonal MTM structures,we proposed a novel multiple splits octagon-shaped MTM configuration.The property of double left-handed frequency bands were validated by both simulation results and equivalent circuit model.Gain enhancement were achieved as expected in the two left-handed frequency bands by loading with the proposed octagon-shaped MTM superstrate.4.A kind of normal incidence MTM was also introduced to act as the superstrate of the transmitting MPA and the gain enhancement was obtained as expected.Surface current distribution and electric field were shown to interpret the double negative property.Resonant frequencies at different design parameters were also presented.5.We created the models of MPA and corresponding MTM structures in PCB drawing software and fabricated the samples.We measured the centre resonant frequency of the MPA by vector network analyzer and tested the directivity before and after loading with the MTM superstrate in microwave anechoic chamber.The measured date agree well with the simulated results and we also analyze the differences between the simulation and measurement results.