Physical Sciences and Mathematics Commons^™

Long-Range, Passive Wireless Monitoring Using Energy-Efficient, Electrically-Small Sensor Nodes And Harmonic Radar Interrogator, Ibrahim Nassar

USF Tampa Graduate Theses and Dissertations

This dissertation investigates the use of the harmonic radar technique for passive wireless sensing applications. Issues of DC power consumption, high RF activation power, large node size, and short communication range associated with the existing passive wireless sensing technologies are addressed by the development of novel, completely passive, high efficiency, compact 3-D harmonic sensor nodes. The node transceiver employs a passive frequency doubler to return the second harmonic of the interrogation signal, and electrically-small 3-D antennas to achieve the compactness and high efficiency. The developed nodes fit inside a sphere with a diameter < 3 cm and achieve communication range > 60 m using a 43 dBm EIRP …