I don't understand what it means "dual-circular polarization". I know that circularly polarized antennas work in Left or Right circular polarization. Does it mean that the antenna (dual circular polarization) works in RHCP and LHCP simultaneously?
The intent of this paper is to present a simple and practical method of measuring the phase centre based on real antenna measurements (**broken link removed**). It is assumed that an antenna has a unique phase centre, although antennas in general do not rigorously satisfy this criterion .