HF RFID spiral inductor synthesis and optimization

In this contribution, we discuss a planar spiral inductor synthesis method which generates physical dimensions of a HF RFID inductor according to the specified equivalent circuit parameters. A numerical model for spiral coil based on the partial element equivalent circuit (PEEC) method is combined with nonlinear optimization algorithm to optimize and synthesize coils. The main application is a HF RFID standard antenna for 13.56 MHz. The paper is intended as a manual for designing a HF RFID tag and includes procedure for measuring impedance of coils and chip, and simple fitted formulas for quick calculation of coil parameters in order to achieve required resonance frequency.