Once again, we are proud to present the “GTPG in a Word Cloud” 2018 edition. This is where all of our research paper publications are fed into a word cloud to give an overview of what we worked on last year. Compare this to the 2017 edition. In 2018, “RFID”, “power”, and “antennas” reigned supreme. Picture courtesy www.wordclouds.com.
Qian Yang’s poster of an “Neural Network-Based State Estimation of HIMR RFID System” is now available. The poster was presented in April in Phoenix, AZ during the IEEE RFID 2019 conference.
The PDF of the poster may be downloaded here: Yang Qian’s Poster
Download Cheng Qi’s poster presentation from IEEE RFID 2019 entitled, “Breaking the Range Limit of RFID Localization: Phase-based Positioning with Tunneling Tags,” which was presented in Phoenix, AZ this April. The PDF may be downloaded here: RFID2019Poster_Cheng
M. Alhassoun, M. Varner, G.D. Durgin. “Theory and Design of a Retrodirective Rat-Race-Based RFID Tag“, IEEE Journal on RFID, vol 3, no 1, March 2019, pp 25-34.
Movement toward mm-wave backscatter communications in radio-frequency identification (RFID) systems necessitates seeking designs that compensate for the path loss introduced by the radio channel. A viable, simple, and power-efficient solution is to equip RFID tags with retrodirective arrays, which guarantee reflection with maximal gain in the direction of incidence. In this paper, we build upon a previous work to design and implement an original retrodirective tag in which its feeding network is a properly terminated rat-race coupler. We start by deriving the required terminations that ensure retrodirectivity. Then, we build a retrodirective tag and experimentally compare its radar cross section to that of a single-antenna tag. The measurements reveal that the radar cross section of the proposed retrodirective tag is, on average, approximately 6 dB more than that of a single-antenna tag while both tags have the same field-of-view. From the promising results in this paper, the proposed design is a potential candidate for next-generation microwave and mm-wave RFID tags because it is compatible with low-power reflection amplifiers (e.g., tunnel diodes), it can implement multiple modulation schemes without changing the circuit layout, and it can be implemented using only a single RF switch.