Research On Dual-polarized Wideband Planar Integrated Phased Array Antenna

As an indispensable component of modern wireless systems,active phased array antennas have the advantages of fast beam scanning speed,flexible beam forming and high stability.They are widely applied to the fields of radar,satellite communications,electronic countermeasures,imaging,etc.With the continuous development of wireless communication technology,phased array antennas are gradually developing towards broadband/ultra-wideband,multi-polarization,wide beam scanning range,and high integration.In this thesis,the low profile ultra-wideband dual linearly polarized phased array antenna and the K/Ka band wideband dual circularly polarized phased array antenna are researched based on the background of multi-functional electronic system and high-speed satellite communication system.1.A 6 GHz-18 GHz low-profile ultra-wideband dual linearly polarized phased array antenna is researched.The ultra-wideband antenna is realized based on the tight coupling effect,and an unbalanced feeding structure is utilized to realize the low profile.The metasurface structure replaces the traditional multi-layer dielectric layer as a wide-angle impedance matching structure,which can realize a wide scanning range and further reduce the total profile of the antenna.In addition,the low in-band scattering characteristics are taken into account while achieving good radiation characteristics of the antenna array.An 8×8 dual-polarized prototype is fabricated to validate the proposed antenna.Measured results show that the array operates from 6 GHz to 18 GHz with active VSWR<2.5 at broadside.The profile of the antenna is 0.07?_l(3.5mm)and it can scan up to 75°in E-plane and 60°in H-plane.2.A K/Ka band wideband switchable dual circularly polarized phased array antenna is researched.Considering the requirements of wide axis ratio(AR)bandwidth and dual circular polarization,the K/Ka phased array antenna adopts the dual-channel circular polarization scheme.The left-hand circular polarization(LHCP)and reft-hand circular polarization(RHCP)can be switched by the phase shift of±90°of the module.A slot coupled microstrip antenna is utilized to achieve wide impedance bandwidth and AR bandwidth,and sequential rotation technique is applied to improve the axial ratio bandwidth and the AR performance in the case of large scanning range.In addition,a quasi-coaxial vertical interconnect structure and a cavity back structure are also used to reduce the coupling between adjacent elements and improve the isolation of the antenna array.An 8×8 narrowband prototype is designed,fabricated and measured in the first version.The feeding structure and multi-layer PCB stackup of the antenna are modified in the second version,which expands the bandwidth and improves the radiation performance of the array.The designed broadband antenna array operates at 27.5 GHz-31 GHz(transmitter)and 17.7 GHz-21.2 GHz(receiver).The array can realize switchable dual circular polarization and the AR of the array is less than 0.5 d B at broadside.The phased array is able to scan to ±60°in all planes.