Compact wide-beam circular polarization antenna and feed network

A kind of novel compact wide-beam circular polarization antenna and its feed network are presented.The antenna is composed of four independent radiation units which rotate 90° about the center separately.The miniaturization of the antenna is realized by distributed capacitive load and short point.The feed network is composed of directional coupler and microstrip lines to achieve power division and quartered phase shift.The analysis,simulation and measured results indicate that the antenna's height is less than 0.12λ,the antenna's beam width is greater than 120°,the beam width of axial ratio less than 6dB is greater than 180°,and the characters mentioned above can be obtained in the frequency range over 15% band width,the relative band width of VSWR<2.0 is 16%.The antenna is fabricated by PCB technics and could be integrated to microwave circuit conveniently.The fabrication has low cost and high precision.The structure could also be applied to frequency range higher than S band and has broad prospects of application.