Radio--Transmitter-receivers--Design and construction Internet of Things
Physically and functionally reconfigurable transceivers are critical to the smooth integration of the Internet of Things (IoT) devices with users. In the IoT domain, novel materials (e.g., conductive fabrics, two-dimensional nanomaterials, etc.) introduce flexibility by replacing traditional metals. The flexibility of novel materials comes at the cost of their complex geometry. Due to the unconventional nature of novel materials, new methods must be developed to understand and characterize them for wireless sensing applications. We have developed a novel method to extract the radio frequency (RF) sheet resistance of unconventional conductive surfaces. We applied the method to study the frequency-dependent anomalous conductivity and sheet resistance of conductive MXene. We also explained the physics behind the anomalous behavior of MXene by applying Maxwell's equations. In addition to the characterization challenge, flexible wireless transceivers must also consider their environment. For example, a wearable antenna sensor is affected by its proximity to the human body, sweat, oxidation, etc. As a result, transceivers must be carefully designed to adapt to these environmental factors. While the harsh environmental characteristics seem to have a detrimental effect on sensor performance, it is possible to develop novel sensors by exploiting those characteristics. We have developed an ultra high frequency (UHF) radio frequency identification (RFID) diaper moisture sensor and a real-time intravenous fluid level sensor by utilizing the efficiency degradation phenomenon of omnidirectional antennas in the vicinity of materials with high electric permittivity (water, human body, etc.). We developed a UHF RFID compression sensor for respiratory sensing, and a multimodal Bluetooth low energy (BLE) sensor for COVID-19 monitoring and contact tracing. We developed a pattern reconfigurable UHF RFID reader antenna array that extends the coverage area of commercial reader antennas and enables better user mobility in a given environment. In addition to flexible materials and sensors, we have researched and developed techniques for wireless channel emulation, sensing, and control. The next generation of flexible IoT sensors and systems would bring transformative changes to all aspects of life including healthcare, transportation, wireless communications, and national security.
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Details
Title
Reconfigurable Radio Frequency Transceivers for Next Generation Internet of Things
Creators
Md Abu Saleh Tajin
Contributors
Kapil R. Dandekar (Advisor)
Awarding Institution
Drexel University
Degree Awarded
Doctor of Philosophy (Ph.D.)
Publisher
Drexel University; Philadelphia, Pennsylvania
Number of pages
xxii, 180 pages
Resource Type
Dissertation
Language
English
Academic Unit
College of Engineering (1970-2026); Electrical (and Computer) Engineering [Historical]; Drexel University