Polarization characteristics of a circularly polarized conical beam spherical slot array antenna

This paper reports the polarization characteristics of a so-called circularly polarized conical beam spherical slot array antenna. Integral equations of the magnetic currents over the slots and the electric current on the probe are formulated by using the field equivalent principle and enforcing the boundary conditions. The dyadic Green´s functions are derived to complete the integral equations. The method of moments is a vital tool in determining the unknown currents over the slots and on the probe. The radiation pattern is realized by integrating the currents on the slots and the external dyadic Green´s functions, and the polarization characteristics can be estimated, subsequently. From the numerical results, it is obvious that the cross polarization of the antenna is relatively high. The antenna parameters should be optimized to realize the better polarization conditions, which is under investigation.