Design And Implementation Of Several High-efficiency Planar Array Antenna

With the rapid development of wireless communication technology,the research of electromagnetic wave has also tended to higher frequency bands gradually,especially the millimeter-wave band.As the fourth generation mobile communication technology that has been deployed becomes more and more mature,the development and exploration of the fifth generation mobile communication technology has attracted widespread attention.Accordingly,the demand for fast data rates is increasing.As a result,the broadband,low profile,high efficiency antennas working at millimeter-wave bands have great application prospects.In this thesis,dual-polarized endfire array antennas and slot array antennas based on high-order mode feeding technique were studied.1.A wideband dual-circularly polarized endfire array antenna at millimeter-wave band is studied and designed.An endfire antenna based on septum polarizer is designed as the element for the array.The feeding network is composed of H-plane power dividers based on ridge gap waveguide.Then a 1×8 antenna array is built up with the elements and the feeding network.The results show that the array antenna achieves the impedance bandwidth of 36%,and 3d B axial ratio bandwidth of 48%.2.A 3d B hybrid coupler with 180ophase shift is designed based on 3d B directional coupler and 90oself-compensating phase shifter.Then,a dual-linearly polarized endfire array antenna is achieved by combining the hybrid coupler with the dual-circularly polarized endfire array antenna.The dual-linearly polarized endfire array antenna exhibits the impedance bandwidth of 25%.3.A 4×4 millimeter-wave slot array antenna fed by TE₄₄₀ mode is proposed.A vertical waveguide is used to excite the TE₄₄₀ mode in the antenna cavity,which greatly reduces the structure complexity of array antenna.By using soft surface on both sides of the radiating surface along the metal ridge,the gain of the array antenna is improved.The proposed antenna achieves the impedance bandwidth of 26.7%and the gain of 17d Bi.Then,a 16×16cavity slot array antenna is designed by combining H-plane groove gap waveguide dividers and the proposed 4×4 slot array.4.A 4×4 circularly polarized millimeter-wave slot array antenna fed by TE₄₄₀ mode is studied and designed.A grating dielectric slab is loaded on the top of the 4×4 slot array antenna to achieve the circular polarization radiation.The results indicate that the proposed array antenna has an impedance bandwidth of 24.6%and a 3d B axial ratio bandwidth of23.6%,the gain is around 17d Bic.Finally,A 4×6 cavity slot array antenna fed by TE₄₆₀mode in the millimeter-wave band is designed with 15%bandwidth and the gain of 18.5d Bi.The proposed antennas in this thesis are based on the gap waveguide technology,which have a similar efficiency compared with those based on the traditional waveguide.Meanwhile,the antennas can be easily assembled with several separate layers,which avoiding the welding or fastening with lots of metal screws.