Research On Radiation Manipulation And Antenna Technology Based On Spoof Surface Plasmons Polaritons

Nowadays,wireless communication technology has penetrated into every aspect of human society and has profoundly changed the way of life of human beings.At the same time,the evolving communication needs have put forward more stringent performance and specification requirements for communication systems and antennas.In order to meet the requirements of complex communication environments,new antenna designs not only need to cover a wider operating bandwidth and have a smaller size and weight,but also often need to combine multi-band,multi-mode,multi-beam and other complex operating performances.Spoof surface plasmon polaritons are a kind of human electromagnetic metamaterials that can generate strong confined electromagnetic waves on the surface of periodic structures.In recent years,spoof surface plasmon polaritons have become a research hotspot for newgeneration antennas due to their obvious advantages in crosstalk suppression,miniaturization and expansion of antenna scanning angle.However,there are many challenges in the application of spoof surface plasmon polaritons in high-performance antennas,such as single radiation band,single radiation mode and lack of beam manipulation methods.This dissertation summarizes the basic characteristics and analysis methods of spoof surface plasmon polaritons,explores the radiation control mechanism of spoof surface plasmon polaritons,and constructs the multi-band radiation,multi-mode radiation,beam manipulation and transparency of spoof surface plasmon polaritons antennas.The design methodology and the main work of this dissertation are based on the following five aspects:1.The main electromagnetic characteristics of spoof surface plasmon polaritons,including dispersion characteristics,mode distribution,field confinement,etc.,are systematically summarized.The electromagnetic properties and advantages of spoof surface plasmon polaritons are further exploited,and the radiation manipulation method of spoof surface plasmon polaritons is explored,which lay a solid theoretical foundation for the subsequent work.2.A Z-shape spoof surface plasmon polaritons structure for realizing fast and slow wave dual-band beam scanning is proposed.The single-layer Z-shape spoof surface plasmon polaritons structure is modulated and loaded with patches to form frequency scanning in two bands.The phase difference in the two frequency bands leads to the beam scanning characteristics of the fast-wave and slow-wave frequency bands The spoof surface plasmon polaritons dual-band beam scanning antenna was designed and fabricated,achieving a large scanning angle from-21.5° to 43.1° in the range of 2.8-7.3 GHz,and-47.3° to 22.5° in the range of 13.7-27.4 GHz.Unlike the conventional spoof surface plasmon polaritons antennas operating within a single frequency band,the proposed antenna is capable of achieving independent beam scanning in two operating bands.3.To address the problems of the single radiation mode of traditional spoof surface plasmon polaritons antenna,a dual-mode spoof surface plasmon polaritons antenna is proposed.The proposed double-layer spoof surface plasmon polaritons structure offers stronger field confinement and significant subwavelength effect,which benefit the miniaturization and beam scanning angle antenna.This antenna can work within the operating band of 3-9 GHz,with the beam pointing at +90°.Meanwhile,it can achieve a large angle beam scanning of-90°～±42.5° in 13-34 GHz.The proposed antenna achieves two operating bands and two radiation modes consisting of endfire radiation and beam scanning radiation.4.For the problem that nowadays spoof surface plasmon polaritons antennas mostly operate with dual-beam radiation,a beam manipulation technique based on the field confinement control is proposed.By modulating the shape of the double-layer spoof surface plasmon polaritons unit cell,the electric field distribution can be controlled to realize symmetric or asymmetric field confinement.Thus,the proposed spoof surface plasmon polaritons structure can generate electromagnetic leakage on both sides or one side,further realizing double or single beam radiation.Based on this approach,two antennas with dual-beam radiation and single-beam radiation were designed,processed,and measured.The dual-beam antenna achieves a beam scan angle of 134.3°(-90° to +44.3°)with a gain of 8.03-12.17 d Bi,while the single-beam antenna obtains a beam scan angle of 119°(-77.9° to 41.1°)with a gain of 10.31-14.24 d Bi.The proposed method based on the field confinement control is able to achieve beam number manipulation,large beam scanning angle and low profile of antenna.5.To address the current gap in the research of transparent spoof surface plasmon polaritons antennas,a quasi-one-dimensional spoof surface plasmon polaritons structure is proposed.The quasi-one-dimensional structure can significantly improve the energy confinement,field enhancement and sub-wavelength effect,making the electromagnetic transparency(including optical and RF)of spoof surface plasmon polaritons possible.By adjusting the parameters of the quasi-one-dimensional structure,the properties of spoof surface plasmon polaritons can be controlled,including confinement,operating wavelength,transmission efficiency.The experiments show that the optical and RF transmittances of the quasi-onedimensional structured spoof surface plasmon polaritons reach more than 90%.Based on the above structure,a spoof surface plasmon polaritons transparent end-fire antenna is designed and fabricated.The experimental results verify that the proposed antenna offers stable endfire in the 14.5-15.5 GHz operating band with a gain of 5.9-7.4 d Bi while obtaining excellent optical transparency.This work fills the research gap to a certain extent and makes the transparent spoof surface plasmon polaritons antennas possible.