[IEEE 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Xuzhou, China (2018.7.21-2018.7.24)] 2018 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC) - Capacitive Probe Fed Broadband Circularly Polarized Omnidirectional Antenna

摘要： A (CP) omnidirectional antenna fed by a capacitive probe is presented in this paper. To attain wideband vertical polarization, a circular monopole patch connecting to the ground by a set of shorting pins is applied. Two groups of curved branches are introduced to create wideband horizontal polarization. The CP radiation can be generated with a proper phase difference between the vertical polarization and the horizontal polarization. The antenna is fabricated and measured. It exhibits an impedance bandwidth (VSWR≤2) of 34.6% (ranges from 4.50 to 6.38 GHz) and an axial ratio bandwidth (AR≤3dB) of 33.5% (ranges from 4.60 to 6.45 GHz). The profile of the antenna is merely 0.06λL (λL is the wavelength corresponding to the lowest operating frequency).