A new type of cone-shaped high gain circularly polarized antenna for PCB integration

A new type of antenna having circularly polarization is developed and studied in this paper. The proposed structure consists of two cone-shaped radiators to construct a dipole antenna. One is simply fed by microstrip line and faced up on the top side. The other one is upside down and directly connected to the ground plane on the bottom side. In each identical cone-shaped radiator, by introducing a gap with appropriate size and specific position excites two orthogonal resonant modes with 90 degree phase deference that leads to good circular polarization. A reflector located at 9.4 mm over the antenna, which is capable of achieving large antenna gain (>8.84 dBi). At the operation frequency 5.8 GHz, the return loss is large than −18 dB and the main beam is toward to the direction at θ = 160° and ϕ = 130°. The other design results show the front-to-back ratio can reach to 13.12 dB, the circular polarization axial ratio in the main beam direction is less than 0.94dB, and the 3 dB circularly polarization axial ratio bandwidth is 375 MHz (5650 MHz to 6025 MHz). The sized of this proposed antenna is 4.5cm by 3cm and made out of FR4 (er = 4.3, tanδ = 0.02). Consequently, the antenna is very suitable for integration between different gears such as DVD player, AP, game console and so on.