J4 ›› 2014, Vol. 41 ›› Issue (6): 65-70.doi: 10.3969/j.issn.1001-2400.2014.06.011

• Original Articles • Previous Articles     Next Articles

Temperature monitor suitable for UHF RFID

QI Zengwei;ZHUANG Yiqi;LI Xiaoming;LIU Weifeng;ZHANG Yanlong;REN Xiaojiao   

  1.  (School of Microelectronic, Xidian Univ., Xi'an  710071, China)
  • Received:2013-08-22 Online:2014-12-20 Published:2015-01-19
  • Contact: QI Zengwei E-mail:qizengwei@163.com

Abstract:

A temperature monitor, suitable for UHF RFID, which adopts a double voltage controlled oscillator (VCO) structure, is designed. The monitor can be used in environment temperature detection and in the supply chain. The output of the monitor is related with temperature only, for the impact of the process and supply voltage variation on the absolutely same VCOs can be counteracted. As the time divided module is adopted, the monitor will be shut down after the temperature is detected. In this module, the problem of recounting can be avoided, and the work range of the tag is not reduced. The design was implemented in SMIC 0.18μm 2P4M EEPROM process. The read and write range of the tag is 6m and 2.5m respectively. And the temperature error is less than ±1.5℃ during the range of-40℃~+85℃ with an accuracy of 0.5℃.

Key words: ultra high frequency radio frequency identification, temperature monitor, double voltage controlled oscillator, temperature error