Phased multi-sine array for simultaneous wireless information and power transfer at extreme frequencies
Basak, Dona (2025)
2025
Sähkötekniikan DI-ohjelma - Master's Programme in Electrical Engineering
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
Hyväksymispäivämäärä
2025-12-31
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-2025121511698
https://urn.fi/URN:NBN:fi:tuni-2025121511698
Tiivistelmä
This thesis studies simultaneous wireless information and power transfer (SWIPT) in the radiative near-field at sub-terahertz frequencies, targeting indoor Internet-of-things applications. A massive, low-cost transmit array architecture is used in which each antenna element transmits a single tone with controllable phases. By controlling the phase of each element, sinusoids at different frequencies combine over-the-air at specific focal points and in time, forming a multi-sine waveform that aligns periodically to concentrate RF power while conveying data.
A system model for near-field propagation with multi-sine synthesis is developed and the special cases of pure power transfer and pure information transfer are derived from the joint formulation. An optimization algorithm based on augmented Lagrangian projected gradient descent method is developed to determine transmit phases. The goal is to maximize the power delivered to the energy harvesting device while simultaneously meeting the required signal quality at the information receiver. The system's functionality is examined by assessing how effectively the array adapts its phase settings to balance power and information delivery, depending on variations in the user's position. This behavior is characterized in terms of the gain relative to a reference single antenna placed at the array’s center, demonstrating the advantages of employing an array architecture.
The system performance is evaluated by analyzing the relationship between performance metrics (i.e., received power for the energy harvesting device, target signal-to-noise ratio (SNR) for the information receiver and geometrical separation between users in terms of angular and radial distance) within the radiative near-field region. System-level simulations further illustrate how communication quality and power-transfer efficiency vary with the spatial placement of users, accounting for the distinct path losses from each antenna element. These results highlight the spatial sensitivity of near-field SWIPT and emphasize the potential of phased-array architectures to effectively manage simultaneous power and information delivery.
A system model for near-field propagation with multi-sine synthesis is developed and the special cases of pure power transfer and pure information transfer are derived from the joint formulation. An optimization algorithm based on augmented Lagrangian projected gradient descent method is developed to determine transmit phases. The goal is to maximize the power delivered to the energy harvesting device while simultaneously meeting the required signal quality at the information receiver. The system's functionality is examined by assessing how effectively the array adapts its phase settings to balance power and information delivery, depending on variations in the user's position. This behavior is characterized in terms of the gain relative to a reference single antenna placed at the array’s center, demonstrating the advantages of employing an array architecture.
The system performance is evaluated by analyzing the relationship between performance metrics (i.e., received power for the energy harvesting device, target signal-to-noise ratio (SNR) for the information receiver and geometrical separation between users in terms of angular and radial distance) within the radiative near-field region. System-level simulations further illustrate how communication quality and power-transfer efficiency vary with the spatial placement of users, accounting for the distinct path losses from each antenna element. These results highlight the spatial sensitivity of near-field SWIPT and emphasize the potential of phased-array architectures to effectively manage simultaneous power and information delivery.