Devices for terahertz retromodulation

The future of wireless communications will require an eventual transition from current wireless carrier frequencies in the low tens of gigahertz to hundreds of gigahertz and even low terahertz. This transition comes with a technological challenge since wireless transmitters for frequencies above 300 GHz are bulky and consume a significant amount of power. This limits their use to fixed installations and cannot be practically implemented for handheld mobile devices. Consequently, handheld mobile devices cannot transmit data with carrier frequencies over 300 GHz. This thesis proposes a novel solution to this challenge through the introduction of passive THz communication links. A passive THz link uses a retromodulator on a mobile device to return power transmitted by a fixed transceiver. This return power is encoded with data by the retromodulator enabling the mobile device to effectively transmit data at carrier frequencies above 300 GHz without needing an onboard THz transmitter. The goal of this thesis is to discover if a passive THz link is feasible given current technology for THz transmitters, detectors, and retromodulators. Theoretical predictions based on the work of other in the literature is presented first followed by an in-depth design and analysis of technologies required for THz retromodulation. Finally, a prototype THz retromodulator is designed and characterized to provide a true measure of the feasibility of passive uplinks. The results of a link budget analysis using the prototype THz retromodulator show that passive THz uplinks are indeed possible given current technology. This is the first known demonstration of THz retromodulation and will allow low-power handheld mobile devices to operate in bidirectional wireless THz communication system without the need for a THz transmitter.Applied Science, Faculty ofEngineering, School of (Okanagan)Graduat