In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far-field low-power-density energy-harvesting technology is thoroughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capabilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

http://users.ece.gatech.edu/etentze/Procs14_Sangkil.pdf

Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms

In this paper, various ambient energy-harvesting technologies (solar, thermal, wireless, and piezoelectric) are reviewed in detail and their applicability in the development of self-sustaining wireless platforms is discussed. Specifically, far- field low-power-density energy-harvesting technology is thor- oughly investigated and a benchmarking prototype of an embedded microcontroller-enabled sensor platform has been successfully powered by an ambient ultrahigh-frequency (UHF) digital TV signal (512-566 MHz) where a broadcasting antenna is 6.3 km away from the proposed wireless energy-harvesting device. A high-efficiency dual-band ambient energy harvester at 915 MHz and 2.45 GHz and an energy harvester for on-body application at 460 MHz are also presented to verify the capa- bilities of ambient UHF/RF energy harvesting as an enabling technology for Internet of Things and smart skins applications.

Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms This paper presents various ambient energy-harvesting technologies and investigates their applicability in the development of self-sustaining wireless platforms.

The vision of embedding connectivity into billions of everyday objects runs into the reality of existing communication technologies -- there is no existing wireless technology that can provide reliable and long-range communication at tens of microwatts of power as well as cost less than a dime While backscatter is low-power and low-cost, it is known to be limited to short ranges This paper overturns this conventional wisdom about backscatter and presents the first wide-area backscatter system Our design can successfully backscatter from any location between an RF source and receiver, separated by 475 m, while being compatible with commodity LoRa hardware Further, when our backscatter device is co-located with the RF source, the receiver can be as far as 28 km away We deploy our system in a 4,800 ft2 (446 m2) house spread across three floors, a 13,024 ft2 (1210 m2) office area covering 41 rooms, as well as a one-acre (4046 m2) vegetable farm and show that we can achieve reliable coverage, using only a single RF source and receiver We also build a contact lens prototype as well as a flexible epidermal patch device attached to the human skin We show that these devices can reliably backscatter data across a 3,328 ft2 (309 m2) room Finally, we present a design sketch of a LoRa backscatter IC that shows that it costs less than a dime at scale and consumes only 925 mW of power, which is more than 1000x lower power than LoRa radio chipsets

https://dl.acm.org/doi/pdf/10.1145/3130970

LoRa Backscatter: Enabling The Vision of Ubiquitous Connectivity

In recent few years, the antenna and sensor communities have witnessed a considerable integration of radio frequency identification (RFID) tag antennas and sensors because of the impetus provided by internet of things (IoT) and cyber-physical systems (CPS). Such types of sensor can find potential applications in structural health monitoring (SHM) because of their passive, wireless, simple, compact size, and multimodal nature, particular in large scale infrastructures during their lifecycle. The big data from these ubiquitous sensors are expected to generate a big impact for intelligent monitoring. A remarkable number of scientific papers demonstrate the possibility that objects can be remotely tracked and intelligently monitored for their physical/chemical/mechanical properties and environment conditions. Most of the work focuses on antenna design, and significant information has been generated to demonstrate feasibilities. Further information is needed to gain deep understanding of the passive RFID antenna sensor systems in order to make them reliable and practical. Nevertheless, this information is scattered over much literature. This paper is to comprehensively summarize and clearly highlight the challenges and state-of-the-art methods of passive RFID antenna sensors and systems in terms of sensing and communication from system point of view. Future trends are also discussed. The future research and development in UK are suggested as well.

/pdf/a-review-of-passive-rfid-tag-antenna-based-sensors-and-30xe8avb4i.pdf

A Review of Passive RFID Tag Antenna-Based Sensors and Systems for Structural Health Monitoring Applications

This paper describes the design of a low power, energy-efficient CMOS smart temperature sensor intended for RFID temperature sensing. The BJT-based sensor employs an energy- efficient 2nd-order zoom ADC, which combines a coarse 5-bit SAR conversion with a fine 10-bit ΔΣ conversion. Moreover, a new integration scheme is proposed that halves the conversion time, while requiring no extra supply current. To meet the stringent cost constraints on RFID tags, a fast voltage calibration technique is used, which can be carried out in only 200 msec. After batch calibration and an individual room-temperature calibration, the sensor achieves an inaccuracy of ±0.15°C (3σ) from -55°C to 125°C . Over the same range, devices from a second lot achieved an inaccuracy of ±0.25°C (3σ) in both ceramic and plastic packages. The sensor occupies 0.08 mm2 in a 0.16 μm CMOS process, draws 3.4 μA from a 1.5 V to 2 V supply, and achieves a resolution of 20 mK in a conversion time of 5.3 msec. This corresponds to a minimum energy dissipation of 27 nJ per conversion.

/pdf/a-cmos-temperature-sensor-with-a-voltage-calibrated-55sw59cspt.pdf

A CMOS Temperature Sensor With a Voltage-Calibrated Inaccuracy of $\pm$ 0.15 $ ^{\circ}$ C (3 $\sigma$ ) From $-$ 55 $^{\circ}$ C to 125 $^{\circ}$ C

This paper presents a system-on-chip passive RFID tag with an embedded temperature sensor for the EPC Gen-2 protocol in the 900-MHz UHF frequency band. A dual-path clock generator is proposed to support both applications with either very accurate link frequency or very low power consumption. On-chip temperature sensing is accomplished with a time-readout scheme to reduce the power consumption. Moreover, a gain-compensation technique is proposed to reduce the temperature sensing error due to process variations by using the same bandgap reference of the tag to generate bias currents for both the current-to-digital converter and the clock generator of the sensor. Also integrated is a 128-bit one-time-programmable (OTP) memory array based on gate-oxide antifuse without extra mask steps. Fabricated in a standard 0.18- μm CMOS process with analog options, the 1.1-mm2 tag chip is bonded onto an antenna using flip-chip technology to realize a complete tag inlay, which is successfully demonstrated and evaluated in real-time wireless communications with commercial RFID readers. The tag inlay achieves a sensitivity of -6 dBm and a sensing inaccuracy of ±0.8° C (3 σ inaccuracy) over operating temperature range from -20°C to 30°C with one-point calibration.

/pdf/a-system-on-chip-epc-gen-2-passive-uhf-rfid-tag-with-4vei5e4r0a.pdf

A system-on-chip EPC Gen-2 passive UHF RFID tag with embedded temperature sensor

Conventional design methodologies for EPC RFID tags focused on minimizing the power consumption of each building block to obtain the maximum achievable communication distance. In this work, we analyze different operation states of the RFID tag and their corresponding power consumption characteristics to identify the limiting factor that dictates the communication distance. Based on the analysis, we propose two approaches to extend the communication distance: (1) shaping the load power to track the unbalanced input power to the tag; (2) scheduling the load to average out the large burst power consumption. Simulation results show that the sensitivity can be improved by 1.8dB.

System level power optimizations for EPC RFID tags to improve sensitivity using load power shaping and operation scheduling

http://www.thebreastonline.com/article/S0960977623005088/pdf

Yunxiao Ling

Papers

A system-on-chip EPC Gen-2 passive UHF RFID tag with embedded temperature sensor

System level power optimizations for EPC RFID tags to improve sensitivity using load power shaping and operation scheduling

Prognostic factors and clinical outcomes of breast cancer patients with disease progression during neoadjuvant systemic therapy