Matching Evaluation of Highly Coupled Dipoles Quantified by a Statistical Approach

Electromagnetic coupling between randomly distributed dipole antennas is analyzed statistically. The impedance matrix of a set of dipoles is first calculated with both the induced electromotive force (IEMF) technique and numerical electromagnetic code (NEC) simulator. Then, the input impedance of a surrounded dipole is assessed for any loading of the surrounding dipoles. Cumulative distributed functions for the mismatch of a surrounded dipole are given for different dipole densities and loadings of the surrounding dipoles. This statistical approach is proposed in the context of UHF radio frequency identification (RFID) use cases where tag antennas are concentrated in reduced volumes and the antenna group behavior should be considered.