Committee: 

Dr. Durgin, Advisor     

Dr. Barry, Chair

Dr. Peterson

Abstract:

The objective of the proposed research is to design a low-power, less-complex retrodirective radio-frequency identification (RFID) tag, evaluate its electromagnetic performance, and model its wireless channel. The use of retrodirective tags is inevitable for a complete and reliable integration of next-generation RFID tags and Internet-of-things (IoT) sensors with future generation of wireless technologies such as mm-wave and massive multiple-input multiple-output (MIMO) communications. The benefits of using retrodirective tags are summarized in three major points: First, since retrodirective tags that operate at microwave and mm-wave frequencies have similar propagation properties—in terms of power losses and field-of-view—to the current RFID tags, which operate at ultra-high frequency (UHF) band, high-frequency retrodirective tags maintain the same coverage distance as the UHF tags and permit faster data rate because of the spectrum availability at microwave and mm-wave regimes. Second, retrodirective tags reduce the randomness of the backscatter RFID channel by changing the small-scale statistical behavior of the channel from  double- to single-fading statistics, much like current wireless channels. Third, by sharing some of the spectral bands with future wireless technologies, retrodirective tags would enable fast, compact, and complete wireless connectivity.