Increased Coding Capacity of Chipless RFID Tags Using Radiation Pattern Diversity

In this paper, a method to increase the coding capacity of chipless RFID tags is proposed. This approach is based on the radiation pattern diversity of different resonators topology or different modes of resonance on the same resonator topology. By using two antennas and therefore two mono-stalk measurements, with these tags, it is possible to double the coding capacity without increasing the frequency band of operation. In the present manuscript, conventional chipless RFID loop resonators are considered. Two modes of resonance will he exhibited for this resonator and used to encode data. The novelty is the usage of the same frequency slot to encode multiple bits without interfering together.