Design of a wideband circularly polarized microstrip antenna for compass and GPS

The design of a wideband circularly polarized antenna for BD2 and GPS is described in this paper. This aperture-coupled stacked antenna with low permittivity has the advantage of increasing the bandwidth of gain. The balance-feed by 4-port power-dividing phase shift network is used to improve circularly polarized bandwidth and circularly polarized purity. The simulation results and measured results are consistent. The realized gain of the antenna is more than 4dB during the whole work band of BD2 and GPS while the axial ratio is less than 3dB, and the circularly polarized performance is excellent.