Search Results (1 - 3 of 3 Results)

Sort By  
Sort Dir
 
Results per page  

Maschino, Tyler StephenFREQUENCY-SELECTIVE DESIGN OF WIRELESS POWER TRANSFER SYSTEMS FOR CONTROLLED ACCESS APPLICATIONS
Master of Science, Miami University, 2016, Computational Science and Engineering
Wireless power transfer (WPT) has become a common way to charge or power many types of devices, ranging from cell phones to electric toothbrushes. WPT became popular through the introduction of a transmission mode known as strongly coupled magnetic resonance (SCMR). This means of transmission is non-radiative and enables mid-range WPT. Shortly after the development of WPT via SCMR, a group of researchers introduced the concept of resonant repeaters, which allows power to hop from the source to the device. These repeaters are in resonance with the WPT system, which enables them to propagate the power wirelessly with minimal losses to the environment. Resonant repeaters have rekindled the dream of ubiquitous wireless power. Inherent risks come with the realization of such a dream. One of the most prominent risks, which we set out in this thesis to address, is that of accessibility to the WPT system. We propose the incorporation of a controlled access schema within a WPT system to prevent unwarranted use of wireless power. Our thesis discusses the history of electromagnetism, examines the inception of WPT via SCMR, evaluates recent developments in WPT, and further elaborates on the controlled access schema we wish to contribute to the field.

Committee:

Dmitriy Garmatyuk, PhD (Advisor); Mark Scott, PhD (Committee Member); Herbert Jaeger, PhD (Committee Member)

Subjects:

Computer Engineering; Electrical Engineering; Electromagnetics; Electromagnetism; Engineering

Keywords:

wireless power transfer; WPT; resonance; magnetic resonance; electromagnetism; power security; power encryption; wireless power transfer security; wireless power transfer encryption; SCMR; strongly coupled magnetic resonance; power transfer;

DeLong, Brock JIntegration of Radio Frequency Harvesting with Low Power Sensors
Doctor of Philosophy, The Ohio State University, 2018, Electrical and Computer Engineering
This dissertation gives guidelines for state-of-the-art power harvesters and for optimizing its components, e.g., rectifier, matching network, and antenna, in various applications. A single diode rectifier using a quarter-wave matching circuit with a measured efficiency of 73.7% is also presented. Several experimental demonstrations are included for powering a number of sensors and devices, such as a clock, computer mouse, calculator, thermometer, medical insulin pump, and super capacitor with power management circuitry. To increase the amount of RF harvested power, an array of rectifying antennas (rectennas) is presented and used in experiments up to 60 meters. Wireless power transfer demonstrations at near field distances are also presented. For the latter, we show a strong tolerance to misalignment while delivering high levels of power (1.2 mW over 42 cm). As an application, a medical pump is successfully powered over this distance. Further, bandwidth widening techniques are presented along with rectifier optimizations. To reduce the overall dimensions of the rectenna, miniaturization techniques are discussed. This leads to a rectenna size of 1.5 x 2.5 cm^2, making it ideal for medical or on-body applications. This rectenna was used to successfully activate a body-worn thermometer across 65 cm. In the case of implantable devices, a dielectric matching layer was found useful and validated using pig skin. A related SAR analysis ensured the safety of the proposed RF powering harvesting techniques.

Committee:

John Volakis (Advisor); Asimina Kiourti (Advisor); Liang Guo (Committee Member)

Subjects:

Electrical Engineering; Electromagnetics

Keywords:

power harvesting; wireless power; WPT; medical devices; wireless power transfer; wireless power transmission

Heebl, Jason DanielDevelopment and Characterization of a Tunable Resonant Shielded Loop Wireless Non-Radiative Power Transfer System
Master of Science (M.S.), University of Dayton, 2011, Electrical Engineering
In this thesis, the theory of coupled resonators for non-adiative wireless power transfer are explored from a lumped element circuit perspective. A basic circuit model is developed and standard circuit parameters are defined. A directly fed resonant shielded loop for wireless power transfer is presented. Basic lumped component values and circuit parameters are experimentally extracted for two resonant shielded loops. Optimal efficiency conditions are derived and used to design optimal matching networks. Matching networks are constructed and the system is tested for power transfer efficiency. Two means of producing a tunable system are explored: frequency tuned sources and dynamic matching networks. It is shown that frequency tuned systems cannot achieve maximum efficiencies. A tunable system is constructed and tested. Experimental results show excellent agreement with theory, and the ability to achieve maximum achievable efficiencies.

Committee:

Robert Penno, PhD (Committee Chair); Anthony Grbic, PhD (Advisor); Monish Chatterjee, PhD (Committee Member); Augustine Urbas, PhD (Committee Member); John Weber, PhD (Other); Tony Saliba, PhD (Other)

Subjects:

Electrical Engineering; Electromagnetics; Electromagnetism; Energy; Engineering; Solid State Physics

Keywords:

Wireless; Power; Transfer; WNPT; resonant; shielded loop; non-radiative; wireless power transfer; WPT