Committee: 

Dr. Tentzeris, Advisor    

Dr. Durgin, Chair

Dr. Peterson

Abstract:

The objective of the proposed research is to introduce solutions for low-cost, long-range and energy-autonomous IoT implementations. Since the number of IoT devices will be massive, it is highly desirable to equip them with long-range harvesting and communication capabilities, and to manufacture them using low-cost and environmentally-friendly processes. This work uses a unique structure--the Rotman lens--that takes advantage of the high available transmitted power at mm-wave frequencies and offers a remarkable and highly desirable combination for both long-range harvesting and communication applications: a high gain and wide angular coverage. A second implementation that manages to extend the communication range while keeping a relatively low power consumption relies on the integration of active devices with negative resistance regions capable of generating a modulation factor greater than unity and thus amplifying the backscattered signal. This work uses commercial off-the-shelf tunnel diodes and few passive components to realize an extremely low voltage and low power semi-passive RFID tag at 5.8GHz. Finally, this research also addresses the high cost associated with the use of commercial components--especially at mm-wave frequencies--by investigating the layer-by-layer deposition of conductors, semiconductors and dielectrics using inkjet printing for the realization of fully-printed transistors and Schottky diodes. The printed active devices will be used to introduce a novel sensing mechanism for fully-passive IoT systems, relying on the functionalization of the printed carbon-nanotubes films and the tunability of the Schottky barriers to enable high sensing capabilities with low-cost fabrication.