A novel wideband directional circular polarized antenna with low profile
In order to solve the problems of complex structure and narrow bandwidth of low-profile directional circular polarized antennas,a novel compact directional broadband circular polarized antenna base on the coaxial-like waveguide was proposed.A spiral slot was formed on the upper surface of the coaxial-like waveguide,and the coaxial interface was used for feeding at the inner port of the waveguide.The size of the inner and outer conductors could be adjusted to optimize the antenna reflection coefficient performance with no need of an external balun,and therefore the antenna structure was simplified.In addition,the antenna directional radiation performance could be directly achieved without the ground plane,and the profile was reduced to 0.1λ(λ is the free space wavelength at the lowest frequency).And due to the wide bandpass of the coaxial waveguides,the wide bandwidth of 57％(2.7-4.85 GHz)was achieved.The antenna prototype was fabricated by dielectric integrated waveguide technology and measured to verify the design.Good agreement between the simulation and measurement results was obtained,showing the validity of this design method.Compared with other directional circular polarized antennas,this antenna has compact structure and simple design,avoiding the use of complex feed network,and has a wide bandwidth.
万方数据
维普
