An RF-Powered Wireless Temperature Sensor for Harsh Environment Monitoring With Non-Intermittent Operation

This paper presents a fully integrated RF-powered temperature sensor with non-intermittent operation. The sensor is powered up wirelessly from a 915-MHz incident signal using a power-efficient RF energy harvester, uses a subthreshold ring oscillator that produces a highly temperature-dependent oscillation frequency acting as a temperature-to-frequency converter, and finally transfers the frequency-modulated signal to an external reader using back scattering. The power management circuits are eliminated in the designed sensor to arrive at a minimalistic design. For proper operation, a novel voltage regulator is developed that produces a relatively constant output voltage as the supply voltage of the ring oscillator for a large range of harvested input energy but allows the output voltage to change as a function of the temperature for added temperature sensitivity of the overall sensor. Power consumption of the proposed sensor is only <inline-formula> <tex-math notation="LaTeX">$1.05~\mu\text{W}$ </tex-math></inline-formula> at room temperature, which enables continuous operation of the sensor from an incident energy of −16 dBm. The sensor is tested between −10 °C to 100 °C exhibiting a minimum sensitivity of 238 Hz/°C at −10 °C and a maximum sensitivity of 31.648 kHz/°C at 100 °C. The predicted temperature error is −2.6 °C to 1.3 °C using a two-point calibration within the range of 10 °C to 100 °C. With a conversion time of 25 ms, 0.046 °C (rms) resolution is achieved. Fabricated in IBM’s 130-nm CMOS technology, the proposed sensor occupies a die area of 0.23 mm<sup>2</sup>.

[1]  Veronique Moeyaert,et al.  A 65-nm CMOS battery-less temperature sensor node for RF-powered wireless sensor networks , 2016, 2016 IEEE Wireless Power Transfer Conference (WPTC).

[2]  Gerald Holweg,et al.  An Electro-Magnetic Energy Harvesting System With 190 nW Idle Mode Power Consumption for a BAW Based Wireless Sensor Node , 2011, IEEE Journal of Solid-State Circuits.

[3]  Kambiz Moez,et al.  Hybrid Forward and Backward Threshold-Compensated RF-DC Power Converter for RF Energy Harvesting , 2014, IEEE Journal on Emerging and Selected Topics in Circuits and Systems.

[4]  D. Cheng.  Field and wave electromagnetics , 1983 .

[5]  David Blaauw,et al.  A Fully-Integrated 71 nW CMOS Temperature Sensor for Low Power Wireless Sensor Nodes , 2014, IEEE Journal of Solid-State Circuits.

[6]  Fan Zhang,et al.  A Batteryless 19 $\mu$W MICS/ISM-Band Energy Harvesting Body Sensor Node SoC for ExG Applications , 2013, IEEE Journal of Solid-State Circuits.

[7]  David Blaauw,et al.  9.2 A 0.6nJ −0.22/+0.19°C inaccuracy temperature sensor using exponential subthreshold oscillation dependence , 2017, 2017 IEEE International Solid-State Circuits Conference (ISSCC).

[8]  Gerald Holweg,et al.  A Multifrequency Passive Sensing Tag With On-Chip Temperature Sensor and Off-Chip Sensor Interface Using EPC HF and UHF RFID Technology , 2011, IEEE Journal of Solid-State Circuits.

[9]  J. F. Dickson,et al.  On-chip high-voltage generation in MNOS integrated circuits using an improved voltage multiplier technique , 1976 .

[10]  Kambiz Moez,et al.  A 3.2 V –15 dBm Adaptive Threshold-Voltage Compensated RF Energy Harvester in 130 nm CMOS , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[11]  Giuseppe Iannaccone,et al.  A 2.6 nW, 0.45 V Temperature-Compensated Subthreshold CMOS Voltage Reference , 2011, IEEE Journal of Solid-State Circuits.

[12]  Yuan Taur,et al.  Fundamentals of Modern VLSI Devices , 1998 .

[13]  Yuanjin Zheng,et al.  An Energy Autonomous 400 MHz Active Wireless SAW Temperature Sensor Powered by Vibration Energy Harvesting , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[14]  Giuseppe Palmisano,et al.  A 90-nm CMOS 5-Mbps Crystal-Less RF-Powered Transceiver for Wireless Sensor Network Nodes , 2014, IEEE Journal of Solid-State Circuits.

[15]  J Olivo,et al.  Energy Harvesting and Remote Powering for Implantable Biosensors , 2011, IEEE Sensors Journal.

[16]  K. Mayaram,et al.  Efficient Far-Field Radio Frequency Energy Harvesting for Passively Powered Sensor Networks , 2008, IEEE Journal of Solid-State Circuits.

[17]  D. Yamazaki,et al.  A Passive UHF RF Identification CMOS Tag IC Using Ferroelectric RAM in 0.35-$\mu{\hbox {m}}$ Technology , 2007, IEEE Journal of Solid-State Circuits.

[18]  M.P. Flynn,et al.  An RF-powered, wireless CMOS temperature sensor , 2006, IEEE Sensors Journal.

[19]  Edgar Sánchez-Sinencio,et al.  A Fully Integrated Reconfigurable Self-Startup RF Energy-Harvesting System With Storage Capability , 2017, IEEE Journal of Solid-State Circuits.

[20]  A. Chandrakasan,et al.  A 180-mV subthreshold FFT processor using a minimum energy design methodology , 2005, IEEE Journal of Solid-State Circuits.

[21]  Yen Kheng Tan,et al.  Energy Harvesting Autonomous Sensor Systems: Design, Analysis, and Practical Implementation , 2013 .

[22]  SeongHwan Cho,et al.  A 95nW ring oscillator-based temperature sensor for RFID tags in 0.13µm CMOS , 2009, 2009 IEEE International Symposium on Circuits and Systems.

[23]  Hamid Jabbar,et al.  RF energy harvesting system and circuits for charging of mobile devices , 2010, IEEE Transactions on Consumer Electronics.

[24]  Christer Svensson,et al.  Trading speed for low power by choice of supply and threshold voltages , 1993 .

[25]  U. Kaiser,et al.  A low-power transponder IC for high-performance identification systems , 1995 .

[26]  Fernando Rangel de Sousa,et al.  An RF-powered temperature sensor designed for biomedical applications , 2013, 2013 26th Symposium on Integrated Circuits and Systems Design (SBCCI).

[27]  Ping-Hsuan Hsieh,et al.  An RF Energy Harvester With 44.1% PCE at Input Available Power of -12 dBm , 2015, IEEE Transactions on Circuits and Systems I: Regular Papers.

[28]  Giuseppe Palmisano,et al.  A 90-nm CMOS Threshold-Compensated RF Energy Harvester , 2011, IEEE Journal of Solid-State Circuits.

[29]  Patrick Chiang,et al.  0.56 V, –20 dBm RF-Powered, Multi-Node Wireless Body Area Network System-on-a-Chip With Harvesting-Efficiency Tracking Loop , 2014, IEEE Journal of Solid-State Circuits.

[30]  Yuan-Hua Chu,et al.  A Wide-Range Level Shifter Using a Modified Wilson Current Mirror Hybrid Buffer , 2014, IEEE Transactions on Circuits and Systems I: Regular Papers.

[31]  David D. Wentzloff,et al.  A 10 mV-Input Boost Converter With Inductor Peak Current Control and Zero Detection for Thermoelectric and Solar Energy Harvesting With 220 mV Cold-Start and $-$14.5 dBm, 915 MHz RF Kick-Start , 2015, IEEE Journal of Solid-State Circuits.

[32]  Jianping Guo,et al.  A 6-$\mu$ W Chip-Area-Efficient Output-Capacitorless LDO in 90-nm CMOS Technology , 2010, IEEE Journal of Solid-State Circuits.

[33]  Roc Berenguer,et al.  Full Passive UHF Tag With a Temperature Sensor Suitable for Human Body Temperature Monitoring , 2010, IEEE Transactions on Circuits and Systems II: Express Briefs.

[34]  Kambiz Moez,et al.  Fully-integrated passive threshold-compensated PMOS rectifier for RF energy harvesting , 2013, 2013 IEEE 56th International Midwest Symposium on Circuits and Systems (MWSCAS).

[35]  Y. Nemirovsky,et al.  Temperature sensitivity of SOI-CMOS transistors for use in uncooled thermal sensing , 2005, IEEE Transactions on Electron Devices.

[36]  Ke-Horng Chen,et al.  17.10 0.65V-input-voltage 0.6V-output-voltage 30ppm/°C low-dropout regulator with embedded voltage reference for low-power biomedical systems , 2014, 2014 IEEE International Solid-State Circuits Conference Digest of Technical Papers (ISSCC).

[37]  Chun Zhang,et al.  A passive UHF tag for RFID-based train axle temperature measurement system , 2011, 2011 IEEE Custom Integrated Circuits Conference (CICC).