A circularly polarized antenna with conical beam

A novel design of circular polarized antenna with conical beam is present in this paper. The antenna consists of four parts: (1) a horizontally polarized omnidirectional planar loop antenna (2) a vertical monopole (3) a reflector as well as the ground of the monopole (4) a feeding network. The horizontally polarized omnidirectional planar loop antenna and the reflector are combined to realize horizontally polarized conical pattern, while the vertically polarized conical pattern is obtained by a patch loaded monopole with a limited ground plane. Circularly polarized conical pattern can be obtained by exciting the two parts with 90° phase difference. Simulation results are present in the paper. The antenna exhibits an impedance bandwidth (S₁₁<;-10dB) of 60MHz at the centre frequency of 4GHz. The simulation axial ratio bandwidth (AR<;3dB) is about 20MHz. The peak gain is 4.5dBi and appears at around θ=42°.