Summary
International Symposium on Antennas and Propagation
2010
Session Number:2WC1
Session:
Number:2WC1-5
13.56 MHz-RFID Antenna Fabricated with Metal Layer of Standard CMOS Process for Biosensor Applications
Boram Kim, Shigeyasu Uno, Kazuo Nakazato,
pp.-
Publication Date:2010/11/23
Online ISSN:2188-5079
Summary:
Radio frequency identification (RFID) technology is a generic term that is used to describe a system that transmits the information of a tag wirelessly, using electromagnetic wave or inductive coupling. Depending on integrated circuit and antenna technology development, RFID has been used in various applications; smart card, factory automation system, toll gates for motor vehicles and container control system. Recently, other application examples has reported that RFID biosensor chips integrates the RFID and biosensor for inexpensive, small and subaqueous sensing system [1]. In this case, integration of an on-chip antenna with RFID tags has significant advantages for small size and low cost tag fabrication. There have been several publications on RFID tags with an on-chip antenna [1-3]. However, many existing on-chip antenna implementations need post process in addition to the standard fabrication process, such as external chip-coil [1], gold plating [2] and thick oxide [3]. Therefore, the additional fabrication time and cost are required for the post process. In this paper, we simplify process and reduce cost by integrating chip and on-chip spiral inductor RFID tag antenna that is fabricated with metal interconnect layer of standard complementary metal oxide semiconductor (CMOS) process. First of all, we select the operating frequency 13.56 MHz that is suitable for the subaqueous measuring system (Fig. 1) and small area spiral inductor. Secondly, we analyse the on-chip spiral inductor by measurement and calculation. Thirdly, we propose the new modulation circuit for on-chip spiral inductor tag antenna and the load modulation is confirmed by measurement. Finally, the 212 kHz amplitude shift keying (ASK) transmission is shown in water by using on-chip spiral inductor RFID tag antenna and new modulation circuit. With such advances, low cost, small size and simple process on-chip tag antenna can be expected for the RFID biosensor applications.