Chipless RFID Reading Method Insensitive to Tag Orientation

This article presents a new reading method which is able to decode the backscattered signal of a chipless tag without any assumption on its orientation. The method is analytically justified by a model and can be applied to any known scatterers or chipless tags composed of multiple resonators. The presented approach is based on two orthogonal measurements in co-polarization on the reader part and can be optionally combined with time gating. Finally, read range is not reduced with this method since the entire energy of the chipless tag's antenna mode is exploited by the reader.