Wirelessly Powered Sensor Transponder for UHF RFID

Mobile-phone-readable 2.45GHz passive digital sensor tag

“…Besides, most of the passive sensor tags available work at 13.56MHz -leading to a very short communication distance (at most a few cm) -, and measure temperature (such as [2]). Recently, passive sensor tags with capacitive sensors and working at 860-960MHz have been reported [3] [4].…”

C5.1 - Sensor Based RFID-Identification System

“…An overview of the trends and latest achievements in this field bringing in play "smart RFID" with increased connectivity and additional facilities can be found in [1]. Nowadays one remarks an increasing interest for intelligent tags, provided with sensing capabilities and able to save and store the acquired information related to both identity and measured parameters (see for example [2,3]). Commercial RFID tags that measure temperature are available [4].…”

An ultra-low power consumption 1-V, 10-bit succesive approximation ADC

“…In many applications, such as wireless sensor networks [1][2][3], biomedical implants [3] or UHF RFID tags [4], data conversion demands stringent requirements on power consumption efficiency in order to preserve energy resources as much as possible. In these scenarios, speed requirements are not a serious concern (data rates below 1MS/s are enough in most cases) and only moderate resolutions are required (typically between 6 and 10-bit).…”

“…Among different ADCs, the Successive Approximation (SA) architecture [1][2][3][4][5][6][7][8][9][10][11] has become a very popular approach for low-power, low-voltage application due to its reduced analog content, always difficult to design under low-V DD conditions. Additionally, they provide a good trade-off between performance and power consumption, within small silicon area.…”