Simple and adaptive UHF RFID modulator using defected ground structure and practical measurement on reader-to-tag communication

✍ Scribed by Jin-Woo Jung; Hyoung-Hwan Roh; Jun-Seok Park

• Book ID: 102949222
• Publisher: John Wiley and Sons
• Year: 2008
• Tongue: English
• Weight: 935 KB
• Volume: 50
• Category: Article
• ISSN: 0895-2477
• DOI: 10.1002/mop.23780

✦ Synopsis

Abstract

An extended work on DGS modulator, which was presented before on Microwave and Optical Technology Letters Society, shall be adaptive performance and practical implementation and measurement. A DGS modulator is motivated from three benefits that can be obtained from defected ground structure; an extensive resonance, size reduction, and excellent stopband characteristic. An extensive resonance via a microstrip ground plane configuration, which includes a varactor diode bridging microstrip transmission line with variable capacitance provision that can be controlled, gives on/off switching and its attenuation level (OOK is a 100%, and which less than 100% can be ASK) that plays the key role of the ASK and OOK modulation process. A varactor diode is under control of a micro control unit that can be controlled by user interface software; therefore, user can monitor communication states while each operational sequence of a varactor diode can be controlled. Sharper phase and more precise data modulation can be achieved after several tuning works and practical trials. A modulation index (about 90–93%) with stable tag responses over the target bands (860–960 MHz, centered 912 MHz) was verified through the practical measurements on the RFID reader communication using ASK. And when a modulation index was nearly 99% (∼98.8%), this is considered to be an OOK. Overall radio communications are with EPC class‐1 Gen2 Type‐B and Type‐C passive tags, respectively. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 2646–2651, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23780