Polarization Conversion from a Two-Port Impedance Loaded Tag

The electromagnetic clutter mitigation is increasingly demanded for achieving the indoor identification and long-range reading of wireless and passive sensor tags. In this paper, a new Polarization Diversity scheme is proposed to reduce the clutter and potentially, to increase the reader to tag separation distance. The proposed wireless tag is a two-port patch antenna loaded by proper passive impedances. When illuminated by a circularly polarized electromagnetic field, the proposed tag backscatters a linearly or circularly polarized field, depending on the choice of four passive load impedances. This polarization conversion is then easily controlled, and can be advantageously implemented to improve the existing wireless systems by reducing the line-of-sight environment clutter and, from this, increasing reader-to-tag separation distance.