Unlocking the Potential of Low-Cost High-Resolution Sensing with Analog BackscatterShow others and affiliations
2024 (English)Conference paper, Published paper (Refereed)
Abstract [en]
Analog backscatter enables sensing and communication while consuming significantly lower power than digital backscatter. An analog backscatter tag maps sensor readings directly to backscatter transmissions avoiding power hungry blocks such as ADCs. The sensor value variations are backseat-tered atop a carrier as changes in frequency and amplitude. Frequency variations are commonly used in backscatter, to avoid the strong self-interference from the carrier. The range of the sensor output linearly maps to the range of base-band frequency variation. Hence a sensor with a wider output range requires a larger base-band frequency range to encode sensor data. This increases the tag oscillator’s switching frequency and hence the tag’s power consumption. We propose to use higher order harmonic frequencies which allows us to reduce the tag switching frequency and read sensor data even when the carrier masks the fundamental frequency. Our system design lowers the cost and power consumption of the analog backscatter system making it suitable for mobile-based sensing applications. We present experimental results demonstrating the viability of our approach and implement a complete system that includes a low-cost radio receiver. Using a carrier with 0 dBm power, we detect the 15th harmonic up to three meters resulting in 15 times more frequency resolution than the fundamental while reducing the tag oscillator’s power consumption by more than 43%. The 7th harmonic is visible up to 18 meters. Increasing the carrier power enables the detection of additional harmonic frequencies.
Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers Inc. , 2024. p. 95-100
Keywords [en]
Backscattering; Costs; Harmonic analysis; Analog backscatter; Band frequencies; Base bands; Frequency resolutions; Frequency variation; Harmonic; Low-costs; Power; Sensing; Sensors data; Electric power utilization
National Category
Electrical Engineering, Electronic Engineering, Information Engineering
Identifiers
URN: urn:nbn:se:ri:diva-74621DOI: 10.1109/RFID62091.2024.10582681Scopus ID: 2-s2.0-85199886254OAI: oai:DiVA.org:ri-74621DiVA, id: diva2:1887243
Conference
2024 IEEE International Conference on RFID, RFID 2024. Cambridge. 4 June 2024 through 6 June 2024
Note
This work has been financially supported by the Swedish Research Council (Grants 2018-05480 and 2021-04968) and the Swedish Foundation for Strategic Research.
2024-08-072024-08-072024-08-07Bibliographically approved