ASK modulator for 900‐MHz RFID system with defected ground structure

Abstract

In this article, an amplitude shift keying (ASK) modulator with defected ground structure (DGS) is proposed for UHF radio frequency identification (RFID) system. Proposed variable DGS resonator with a varactor diode will be able to adjust the resonance frequency to achieve the ASK modulation. The variable resonance characteristics can be obtained by controlling capacitance of varactor diode, placed on the defected ground. To clarify corresponding method, we manufactured RFID system board using variable DGS resonator and measured the corresponding performance. As almost 93% of extracted data from modulation index characteristic is satisfied with both EPC class‐1 Gen2 Type‐B and Type‐C standard protocols, we obtained stable tag response of RFID system. © 2007 Wiley Periodicals, Inc. Microwave Opt Technol Lett 49: 2513–2516, 2007; Published online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.22760

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

“…The SGS length is corresponding with the half guide-wavelength at around 4 GHz. Figure 1(b) shows the simulated frequency response for different radius r of SGS by using a full-wave EM simulation IE3D [10].…”