Research On Fabry-Perot Resonant Cavity Antenna And Dual Polarized Antenna

Since the beginning of the 21^st century,the pace of human exploration of the world has greatly accelerated,and the communication environment has become more complex and ever-changing.The arrival of the internet era has also brought more close links between humans,more frequent exchanges,and greater transmission of information.Therefore,communication systems need more excellent and stable performance.Antennas have always served as the eyes and ears of wireless communication systems.It is of great practical significance to study higher performance and multi-functional antennas.The research on multi-polarization and miniaturization of antennas has received much attention.The research work in this paper focuses on the following aspects:1.The principle of small-aperture,low sidelobe level Fabry-Perot resonant cavity antenna is analyzed.Based on this principle,the structure of loading two magnetic walls on the E plane and loading two electric walls on the H plane is used to reduce the sidelobe level of the antenna and guarantee a relatively high gain too.Through simulation and experimental verification,the antenna has high gain and good sidelobe performance.2.Based on the research of small-aperture,linearly polarized and low sidelobe level Fabry-Perot resonator antenna,the same structure is used to shield the side of the antenna cavity.According to the principle of linear-circular polarization conversion,a frequency selective surface?FSS?structure with polarization conversion function is proposed.Based on this,a small-aperture,circularly polarized and low sidelobe level Fabry-Perot resonator antenna fed by linearly polarized source is designed,which is simple and easy to be manufactured,and it does not require a complicated feeding network3.Based on the linear-circular polarization conversion principle,using FSS structure with the function of polarization conversion,combining two layers of uniform dielectric slabs as the cover,a high-gain orthogonal circularly polarized antenna integrated with short horn with a frequency ratio of 1.03 at two frequencies is designed and implemented4.A low-profile dual-polarized printed dipole antenna coupled by an L-shaped probe is designed.The theory is based on the characteristics of the zero-reflection phase of the Artificial Magnetic Conductor?AMC?in a specific frequency band.The AMC structure served as a reflector of the antenna can greatly reduce the profile of the antenna.The spacing between the upper radiating element and the lower reflecting surface of the antenna is reduced from 0.25??with PEC as the antenna reflecting surface?to 0.047??by AMC as the antenna reflecting surface?.Through simulation and experimental verification,the antenna has a large gain when the two ports are respectively fed,and the isolation between the ports is higher than 32dB.