Phase centre is defined as a point (or a set of points) in space from which, when emitted, far-field phasefronts or, correspondingly, group-delay fronts are spherical or substantially spherical [1-2]. That is, the phase value is constant in a certain angular area of interest when measured with respect to the coordinate system whose origin is in the PC. However, PC is ambiguous for most of the real-life antennas and its position varies for…