On the design and implementation of efficient antennas for high frequency-radio frequency identification read/write devices

Abstract

This article describes an in-depth methodical approach to the development of efficient high-frequency (HF) antennas for use in radio frequency identification (RFID) systems operating at 13.56 MHz. It presents brief theory relevant to RFID communication and sets up a framework within which features and requirements of antennas are linked to key design parameters such as antenna form-factor and size; RF power level, material and communication protocol. Tuning circuits necessary to adjust the resonance and power matching characteristics of antennas for good transponder interrogation and response recovery are discussed. To validate the approaches outlined, a stepwise design and measurement of an HF antenna for an ISO/IEC 15693 compliant read/write device (RWD) is described. Common practical problems that are often encountered in such design processes are also commented on. The prototyped antenna was tuned, connected to the RWD via a 50 (Formula presented.) coaxial cable and tested.