Design of small implantable RFID antenna for 2.4GHz band for in-body wireless communication

Abstract

Radio frequency identification (RFID) system is developing quickly in recent years, and its industry including logistics management, automatic object identification, etc. Moreover, it is suggested to combine with in-body wireless communication to reduce medical error and receive the patients’ information without connecting cable lines in hospitals. In this paper, we proposed an implantable RFID antenna which is designed to operate at 2.4GHz (2.4-2.485GHz) and matched a IC chip with conjugate impedance of 9.3-j55.2Ω. The good impedance matching can be obtained by adding loop structure, and moreover, miniaturization of antenna is achieved by folded structure. Therefore, the whole size of proposed antenna with glass coating is only 9.3mm × 1.0mm × 1.0mm. The impedance characteristic of implantable RFID antenna is simulated by use of finite element method (FEM) and the experiment is implemented with three-layered phantom which represents human upper arm.