The U.S. transportation sector represented about 28% of all energy consumption in 2018. Petroleum products accounted for 92% of this total energy. Light-duty vehicles are the largest energy consumers in the transportation sector. The high amount of petroleum used by light-duty vehicles creates significant economic and environmental challenges. Electric Vehicles (EVs) have a higher fuel economy and can be emission-free; they are therefore an alternative solution for minimizing the negative environmental impact of internal combustion engine vehicles. However, the adoption of EVs has been limited by their limited driving range, long recharging time, and comparatively higher price. Dynamic wireless charging technology allows for charging the EV battery in motion. Charging pads are embedded in the road and the EV battery is charged while the vehicle is passing over them. This technology not only extends the EV range but also results in a considerable reduction in battery size and capacity. Therefore, dynamic wireless charging solves one of the major issues of EVs, leading to their large-scale adoption. In the first part of this dissertation, a pad optimization methodology is presented to minimize system cost and losses. Using this method, two pads are optimized, built and tested for charging the EV. In the next section, two methods are presented to estimate how much the EV is laterally misaligned with respect to the center of the charging pads. This helps to increase system efficiency and power transfer capability. Finally, new concrete-based material is presented and studied to reduce the charging pad cost and increase their durability.

With the emergence of the Internet of things (IoT) networks, the replacement of batteries for IoT devices became challenging. In particular, the battery replacement is more expensive and cumbersome for scenarios where there are many IoT devices; or where the IoT devices are in unreachable locations; or when they have to be replaced often. Some IoT devices might be lost or forgotten, and there is a risk of hazardous chemicals leakage and e-waste in large scale in nature. Radio frequency (RF) wireless power transfer (WPT) is an alternative technology for powering those devices. It has been shown that only less than one millionth of the transmitted energy is absorbed by the receivers, the rest is absorbed by the objects in the environment. We can utilize the existing infrastructure for wireless communications such as base stations (BS) to charge IoT devices. The present work is devoted to analyze the feasibility and limitations of the battery-less operation of IoT devices with RF WPT technology and energy harvesting from existing infrastructure for wireless communications. We study the indoor and outdoor scenarios for powering of IoT devices. In the first scenario, we consider an outdoor environment where an IoT device periodically harvests energy from an existing BS and transmits a data packet related to the sensor measurement under shadow fading channel conditions. We analyze the limits (e.g., coverage range) of energy harvesting from a BS for powering IoT devices. We characterize the "epsilon-coverage range, where" is the probability of the coverage. Our analysis shows a tradeoff between the coverage range and the rate of sensor measurements, where the maximal "epsilon-coverage range is achieved as the sensor measurement rate approaches zero. We demonstrate that the summation of the sleep power consumption and the harvesting sensitivity power of an IoT device limits the maximal "epsilon-coverage range. Beyond that range, the IoT device cannot harvest enough energy to operate. The desired rate of the sensor measurements also significantly impacts the "epsilon-coverage range. We also compare the operational domain in terms of the range and measurement rate for the WPT and battery-powered technologies. In the second scenario, we consider the remote powering of IoT devices inside an aircraft. Sensors currently deployed on board have wired connectivity, which increases weight and maintenance costs for aircraft. Removing cables for wireless communications of sensors on board alleviates the cost, however, the powering of sensors becomes a challenge inside aircraft. We assume that the IoT devices have fixed and known locations inside an aircraft. The design problem is to minimize the number of WPT transmitters given constraints based on the cabin geometry and duty cycle of the IoT devices. We formulate a robust optimization problem to address the WPT system design under channel uncertainties. We also derive an equivalent integer linear programming and solve that for an optimal deployment to satisfy the duty cycle requirements of the cabin sensors. / <p>QC 20220223</p><p></p>

The purpose of this paper is to achieve wireless power transfer inside a resonating cavity, and thereby apply this to charge batteries. The idea is to convert radio frequency waves into direct current, which can charge the batteries. This was done by creating an LC-antenna, which in turn was connected to a rectifier. A data logger was also built, this to be able to read and log the power within the cavity to examine its power distribution. Because of COVID-19 restrictions, access to laboratory and equipment was limited. Due to this, smaller experiments where performed to make sure that all parts worked as intended before trying to perform tests inside the cavity resonator. The results were varied, some favorable, some not. However, all experiments gave insight and further understanding on the issue. The cavity operations had varied results. The data logger was able to pick up, at most, 7.6 % of the power output by the function generator. However, some problems arose with the rectifier which resulted in it not working for higher frequencies. Though, it was capable of rectifying RF signals at lower frequencies from a function generator, which was used to charge a battery. Consequently, there was no charging of batteries inside the cavity. However, three dimensional wireless power transfer was achieved. With some improvements to the current designs, the main goal could be accomplished

The next technological revolution, Industry 4.0, is envisioned as a digitally connected ecosystem where machines and gadgets are driven by artificial intelligence. By 2025, more than 75 billion devices are projected to serve this revolution. Many of which are to be integrated into the fabrics of everyday life in the form of smart wireless sensors. Still, two major challenges should be addressed to realize truly wireless and wearable sensors. First, the sensors should be flexible and stretchable, allowing for comfortable wearing. Second, the electronics should scavenge the energy it requires entirely from the environment, thus, eliminating the need for batteries, which are bulky, create ecological problems, etc. By addressing these two challenges, this dissertation paves the way for truly wearable sensors. The first part of the dissertation introduces a biocompatible magnetic skin with exceptional physical properties. It is highly-flexible, breathable, durable, and realizable in any desired shape and color. Attached to the skin of a user, the magnetic skin itself does not require any wiring, allowing to place the electronics and delicate components of the wireless sensor in a convenient nearby location to track the magnetic field produced by the magnetic skin. To demonstrate the performance of the magnetic skin, wearable systems are implemented as an assistive technology for severe quadriplegics, a touchless control solution for eliminating cross contaminations, and for monitoring blinking and eye movement for sleep laboratories. The second part of the dissertation is about wirelessly powering wireless sensors. In doing so, radio frequency (RF) rectifiers are a bottleneck, especially for ambient RF energy harvesting. Therefore, two RF rectifiers are introduced in standard CMOS technologies. The first architecture utilizes double-sided diodes to reduce the reverse leakage current, thus achieving a high dynamic range of 6.7 dB, -19.2 dBm sensitivity, and 86% efficiency. The second rectifier implements a dual-mode technique to lower the effective threshold voltage by 37%. Consequently, it achieves a 38% efficiency at −35 dBm input power and a 10.1 dB dynamic range while maintaining the same efficiency and sensitivity. Ultimately, combining these wireless powering techniques with the magnetic skin allows for truly wireless and wearable solutions.

Wireless inductive power transfer systems are the only viable option for transferring energy to a moving vehicle. In recent years, there has been a great deal of interest in in-motion vehicle charging. The dominant technology thus far for in motion charging is elongated tracks, creating a constant eld for the moving vehicle. This technology suers from high volt ampere ratings and lower efficiency of 70%. On the other hand, stationary charging systems can demonstrate efficiency up to 95%. This thesis proposes lumped coils, similar to stationary charging coils for in-motion electric vehicle charging application. This novel primary coil architecture introduces new challenges in optimization and control. Traditional design of wireless inductive power transfer systems require designer experience, use of time consuming 3D FEM algorithms and lacks the comprehensive nature required for these systems. This thesis proposes two new optimization algorithms for the design problem which are comprehensive, based on only analytical formulations and do not need designer experience. There are challenges in the control of power transfer as well. Higher efficiency comparable to stationary systems can only be realized with proper synchronization of primary voltage with the vehicle position. Vehicle position detection and communication introduce significant cost and convenience issues. This thesis proposes a novel control algorithm which eliminates the need for vehicle position sensing and yet transfers the required percentage of energy. Both the optimization and control algorithms are verified with hardware setup.

Wireless power transfer is a method of transferring electric power from a transmitter to a receiver without requiring any physical connection between the two. Dynamic Wireless Power Transfer (DWPT) entails having the transmitters buried under the roadway and the receiver unit being installed on the Electric Vehicle (EV). In this method, EVs are charged while driving over the transmitters as they receive bursts of electric energy at the time of significant alignment between transmitters and receivers. Compared to the stationary charging method which involves parking the EV for long hours for a full charge, the dynamic charging method (i.e., DWPT) offers convenience as the vehicle gets charged while driving. It also facilitates extended driving range of EVs. Despite offering these advantages, DWPT causes a few significant issues. DWPT charging results in a transient power profile both at grid side and EV side, which not only hampers grid-side regulation but also affects EV-battery longevity. To address these two issues, both grid-side and EV-side energy management are needed to be employed to protect the grid and the vehicle from sudden exposure to harmful power transients. In this dissertation, the grid-side and EV-side energy management methods have been investigated. Firstly, a detection system to safely detect the vehicle on charging lane is proposed. This detection system is used to facilitate safe and efficient operation of DWPT chargers on EV roadways. Secondly, A novel DWPT system is proposed, which reduces the grid-side power transients with minimal additional hardware requirements. Finally, an EV-side energy management system is proposed which reduces the exposure of EV batteries to pulsating DPWT-power, thereby helping batteries to last longer.

Indiana University-Purdue University Indianapolis (IUPUI) / This thesis is an examination of one of the main technologies to be developed on the path to Space Solar Power (SSP): Wireless Power Transfer (WPT), specifically power beaming. While SSP has been the main motivation for this body of work, other applications of power beaming include ground-to-ground energy transfer, ground to low-flying satellite wireless power transfer, mother-daughter satellite configurations, and even ground-to-car or ground-to-flying-car power transfer. More broadly, Wireless Power Transfer falls under the category of radio and microwave signals; with that in mind, some of the topics contained within can even be applied to 5G or other RF applications. The main components of WPT are signal transmission, propagation, and reception. This thesis focuses on the transmission and propagation of wireless power signals, including beamforming with Phased Array Antennas (PAAs) and evaluations of transmission and propagation efficiency. Signals used to transmit power long distances must be extremely directive in order to deliver the power at an acceptable efficiency and to prevent excess power from interfering with other RF technology. Phased array antennas offer one method of increasing the directivity of a transmitted beam through off-axis cancellation from the multi-antenna source. Besides beamforming, another focus of this work is on the equations used to describe the efficiency and far field distance of transmitting antennas. Most previously used equations, including the Friis equation and the Goubau equation, are formed by examining singleton antennas, and do not account for the unique properties of antenna arrays. Updated equations and evaluation methods are presented both for the far field and the efficiency of phased array antennas. Experimental results corroborate the far field model and efficiency equation presented, and the implications of these results regarding space solar power and other applications are discussed. The results of this thesis are important to the applications of WPT previously mentioned, and can also be used as a starting point for further WPT and SSP research, especially when looking at the foundations of PAA technology.

To meet the latest requirements of the 6G standards, several techniques have been proposed in the open literature, such as millimeter waves, terahertz communication, and massive MIMO. In addition to these recent technologies, the use of unmanned aerial vehicles (UAVs) is strongly advocated for 6G networks, as the 6G standard will not be dedicated to broadband services, but will rather be oriented towards reduced geographical cellular coverage. In this context, the deployment of UAVs is considered a key solution for seamless connectivity and reliable coverage. Although UAVs are characterized by their high mobility and their ability to establish line-of-sight links, their use is still impeded by several factors such as weather conditions, their limited computing power, and, most importantly, their limited energy. In this work, we are aiming for the novel technology that enables indefinite wireless power transfer for UAVs using laser beams. We propose a novel UAV deployment strategy, based on which we analyze the overall performance of the system in terms of wireless coverage and provide some useful insights. To this end, we use tractable tools from stochastic geometry to model the complex communication system.

Failure of a machine can lead to production downtime and significant financial losses. Condition monitoring is implemented to avoid such downtime and devices can be used to collect data used for monitoring machine health. Vibration data is the most common type of data used for predicting machine failure. To reduce the need for hazardous cables, such devices are often battery-operated, but this can decrease monitoring device lifespans to less than 3 years, if non-rechargeable batteries are used. This thesis first proposes a design framework for implementing radio frequency energy harvesting (RFEH) at a network level. All of the necessary inputs and parameters to ensure the successful implementation of RFEH for a wireless sensor network are explored. A second design framework is then proposed for using RFEH as a source of energy to power devices for condition monitoring. This includes a power analysis of all device components, as well as the design details for an implementation of wireless power transfer using a wireless transmitter and receiver. A comparison of different types of energy sources for the device is given, followed by a case study, using commercially-available components. A simulation is used to analyze the trade-offs for different values of RFEH parameters, trading off the total cost of implementation with the system's lifetime, based on total energy consumed.

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