PEEC antenna modeling of rectangular spiral inductors for RFID systems

Abstract

PurposeThe purpose of this paper is to offer a fast and accurate simulation method for printed spiral radio frequency identification coils and to extract the parameters of an equivalent resonance circuit.Design/methodology/approachThe frequency‐dependent port impedance of a rectangular spiral multi‐turn antenna is simulated with the non‐retarded partial element equivalent circuit (PEEC) method. The discretization settings needed for an accurate modeling of skin and proximity effects at medium frequencies as well as parasitic capacitances are discussed. Two different PEEC approaches are used, a magneto‐quasi‐static (resistive and inductive cells) model and a non‐retarded (capacitive cells included) model in order to extract a reduced equivalent resonance circuit which is beneficial to describe the inductive coupling to further inductors via the transformer concept.FindingsWith optimized mesh settings, the extremely fast simulation can be carried out just in seconds whereas the results compared to a computationally much more expensive CST Microwave Studio® reference solution as well as an analytical direct current solution show errors of only about a few percent.Research limitations/implicationsThe methodology is limited to frequencies up to the first self‐resonant frequency of the coil. In addition, piecewise‐homogeneous materials are implied.Originality/valueSpecialized mesh settings allow for a very fast and accurate simulation of rectangular spiral inductors. A method for the parameter extraction of a resonance circuit is proposed by evaluating two different PEEC models.