Research And Application Of PSOAM Vortex Antenna Based On SSPP

Under the background of the rapidly developing internet era,the spectrum resources are increasingly strained,the wireless services is increasing,and the contradiction between the two is convenient to increase.In order to alleviate the increasing intensification,the Orbital Angular Momentum(OAM)technology stands out among many radio technologies,which can make the use of limited spectrum resources more reasonable and improve the utilization rate of spectrum effectively.However,the OAM beam also has some disadvantages,such as the central black hole,the divergence of the beam in different modes and other problems,the OAM beam are restricted in its practical application.Therefore,in order to solve these problems,the concept of Plane Spiral OAM(PSOAM)was put forward in this environment.The new OAM beam not only has the characteristics of traditional OAM beam,but also can effectively solve the problem of inconsistent beam divergence due to its radial propagation.Meanwhile,different PSOAM modes can propagate in the same direction,which is convenient to realize multi-mode synthesis.Therefore,the new OAM beam can replace traditional OAM beam in radar detection and electromagnetic sensing and other practical applications to provide a new development direction.Surface Plasmon Polariton(SPP)is an electromagnetic wave mode with special properties in the optical frequency band.It is excited at the interface between metal and medium,and can bind the energy to the conductor surface.Besides,its excellent characteristics,such as short working wavelength and transmission cutoff at high frequency,have been applied in various fields for research.Spoof Surface Plasmon Polariton(SSPP)realizes the dispersion characteristics of similar surface plasmon by means of periodic grooving or opening.Because its geometric parameters can affect its dispersion characteristics,it has important research significance for the construction of easily regulated devices or some circuits,which greatly promotes the development of microwave frequency band.In this thesis,a new method for generating and synthesizing PSOAM is proposed.Based on SSPP,the SSPP leaky-wave antenna is constructed firstly.Then,the leaky-wave antenna is constructed into a PSOAM vortex antenna which is researched in detail.Further,the multi-mode PSOAM wave scanning can be realized by combining different PSOAM modes.The main contents of the work are as follows:1.Firstly,the radiation principle of leaky-wave antenna is briefly introduced.Then,the SSPP leaky-wave antenna is designed by means of impedance surface modulation,whose working frequency ranges from 9.5GHz to 10.8GHz.The leaky-wave antenna can scan by changing the frequency and can radiate multiple beams simultaneously.The amplitude and angle of each beam can be controlled independently.2.On the basis of the single wave leaky-wave antenna,we bent the single wave leaky-wave antenna to form a cylindrical resonant cavity antenna,and designed a PSOAM vortex beam antenna based on SSPP.By the bridge to generate ±90° phase difference between the two output ports to realize the switching of the positive and negative PSOAM mode.The antenna operates in the range of 9.5GHz-10.7GHz and realizes different PSOAM modes.3.Based on single-mode PSOAM beam simulation results,in order to improve the PSOAM beam directivity,the linear leaky-wave antenna generating double beam is constructed into a multimode PSOAM vortex antenna,and the multi-mode synthesis is realized at 10 GHz.In addition,by changing the periodic structure of the SSPP leaky-wave antenna according to the rule,the phase of each mode is regulated,so that the beam can realize azimuthal scanning function on the twodimensional plane.