Differential feeding as a concept for the realization of broadband dual-polarized antennas with very high polarization purity

In this paper a new concept for the design of the ultra broadband antennas with dual-orthogonal, linear polarization is introduced. It enables an outstanding polarization decoupling over the very wide frequency range. The antenna built accordingly to this concept can be realized in the planar technology, where the radiation occurs perpendicularly to the antenna surface. This feature is not common in the few dual-polarized ultra wideband antennas introduced in the literature. The concept assures that the phase center of radiation is the same for both polarizations and does not move at all in the whole frequency range. This is very advantageous especially for the impulse-based UWB systems. The coupling between ports is very low. The measurements with the antenna basing on this concept confirm the theoretical assumptions and show very good performance of the device.