Enhancement of RF Tag Backscatter Efficiency With Low-Power Reflection Amplifiers

John Kimionis, Apostolos Georgiadis, Ana Collado, Manos M. Tentzeris

Research output: Contribution to journalArticle

14 Citations (Scopus)

Abstract

Increasing backscatter tag communication ranges is crucial for the development of low-power long-range wireless sensor networks. A major limitation for increasing the signal-to-noise ratio (SNR) for RF identification tags lies in the fact that tag antennas are terminated with passive loads for modulation, which yields reflection-coefficient values less than unity. Recent work in the field has exploited reflection amplifiers that achieve reflection-coefficient values larger than unity to increase the communication range. However, most of these systems rely on increasing the reflection coefficient at one modulation state only, which is suboptimal. In this paper, an analysis is given for the optimal way to utilize a reflection amplifier and how this compares to suboptimal practices. To demonstrate the concept, a tag is designed that achieves reflection-coefficient values higher than unity for both states in the 900-930-MHz band. The two values are antipodal, thus maximizing the tag SNR for a given amplifier. The system comprises of an ultra-low-power reflection amplifier with up to 10.2-dB gain and sub-milliwatt power consumption, and a phase-shift modulator that selectively alternates the phase of the backscatter signal between 0 degrees and 180 degrees. The reflection amplifier-phase modulator system is experimentally characterized in terms of gain, power consumption, and backscatter efficiency.

Original languageEnglish
Pages (from-to)3562-3571
Number of pages10
JournalIEEE Transactions on Microwave Theory and Techniques
Volume62
Issue number12
DOIs
Publication statusPublished - Dec 2014

Keywords

  • Backscatter radio
  • increased singal-to-noise ratio (SNR)
  • reflection amplifier
  • RF identification (RFID) sensors
  • scattering efficiency
  • SENSOR NETWORKS
  • SCATTER RADIO
  • OSCILLATOR
  • SYSTEM

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