Design Of Wideband Resonant Cavity Antenna Based On Metasurface

With the rapid development of mobile communication technology,more and more requirements have been put forward for antennas operating at low frequencies.The FabryPerot resonant antenna has attracted widespread attention due to its small size and high gain.However,the narrowband characteristics of such antennas limits its application scenarios.In this context,this thesis mainly studies the broadband high-gain Fabry-Perot resonator antenna.The research work of this thesis includes the following aspects:1.The working principle of the Fabry-Perot resonant cavity antenna is briefly analyzed with the help of the ray-tracing model,and its parameters are deduced;the influencing factors such as different arrangements of the metasurface,different unit sizes,and different dielectric substrates are analyzed.Simple electromagnetic reflection characteristics analysis;selected and designed a U-slot microstrip antenna as the feed source to form a Fabry-Perot resonant cavity antenna,and compared the effect of the cladding diameter on the antenna performance.2.The broadband resonance conditions for the positive slope phase-frequency reflection characteristics are derived and analyzed.At first,an attempt was made to form a cladding layer with this phase-frequency characteristic from a dielectric substrate,but the structure was too thick,difficult to control,and difficult to process.o get rid of the constraints,a single-layer double-sided metasurface unit based on printing technology was proposed and designed to realize the broadband Fabry-Perot resonant cavity antenna.The principle of metasurface structure is easier to understand by equating the metasurface structure as a circuit model.The design method makes the positive slope phase control convenient,does not depend on the parameters of the dielectric substrate,the design is more flexible,the processing is simple,and the cost is extremely low.3.The single-cavity dual-frequency resonance conditions of the Fabry-Perot resonant cavity antenna are deduced,and the two-sided ring-shaped single-layer singlesided metasurface cladding can independently adjust the resonance frequency,and a broadband dual-polarized antenna is used as the feed antenna.The dual-frequency operation of the resonant cavity antenna is realized to widen the bandwidth.Then,the dual-frequency resonance conditions of the double-cladding layer are analyzed,the different combining methods of the double-cladding layer are analyzed,and the stepped square aperture type metasurface unit is designed,and finally,the dual-frequency operation of the antenna is realized.