Antenna Modeling for Inductive RFID Applications Using the Partial Element Equivalent Circuit Method

In this paper equivalent circuit models of inductive coupled radio frequency identification (RFID) antenna systems are extracted by means of the partial element equivalent circuit (PEEC) method. Each antenna impedance is analyzed separately regarding frequency dependent behavior including skin- and proximity effects as well as parasitic capacitances. On the contrary, the inductive coupling between any two coils is computed for an arbitrary 3D spatial arrangement by a filamentary mutual inductance computation technique, allowing for fast spatial sweeps. Both models are combined to a reduced equivalent circuit that maintains the topology of mutually coupled inductances. The described approach is tested with a conventional reader transponder arrangement and compared with the full PEEC models.