Fred Barlow

Bio: Fred Barlow is an academic researcher from University of Idaho. The author has contributed to research in topics: Power module & Fourier transform. The author has an hindex of 19, co-authored 88 publications receiving 1368 citations. Previous affiliations of Fred Barlow include Virginia Tech & Metropolitan State University of Denver.

Develop procedure for designing fourth order microstrip dual-mode bandpass filters

Abstract: This paper presents a straightforward procedure for designing four order microstrip dual-mode bandpass filters using full-wave electromagnetic (EM) simulation tools. This can be utilized by beginner designer in a microwave filter field, especially for complex distributed microstrip planar structure. The designed methodology was demonstrated by fabricated and measured of several experimental samples of fourth order microstrip dual-mode bandpass filters. The simulated and practical results are obtained.

Curriculum restructure to answer critical needs in packaging for energy efficiency/renewable energy systems, wireless, and mixed-signal systems areas

Abstract: The Electrical Engineering Department at University of Arkansas has been building considerable strength in Energy Efficiency/Renewable Energy Systems, Mixed-Signal, and Wireless Packaging areas. This effort is in coordination with critical other Departments within the College of Engineering; specifically Industrial Engineering and Mechanical Engineering Departments, in addition to the Physics Department within the College of Arts and Science. The High Density Electronics Center (HiDEC), established in 1992 with DARPA funds to conduct research on advanced electronic packaging technologies, enables the educators to interact within the various disciplines to achieve the set objectives of packaging in these areas. The paper will outline the mission of each area, the vision and objectives of the administration, the technical issues to be addressed, the technological challenges and barriers for the Department to face and overcome to make this vision a true reality, and the curriculum restructure. The paper will also outline how critical these strategic areas are for a national academic institution recognition and fulfillment of critical needs for our nation's global competitiveness.

A study of microwave behavior of a thin-print gold ink

Abstract: A newly developed suspension of nanometer size gold particles is utilized to design a thin-print etchable gold paste. The new paste is suitable for screen printing on ordinary 96% alumina substrates and provides an ultra thin, but very dense, fired film. The thinness of the film results in substantial cost savings, while at the same time allowing for the fabrication of very narrow lines. Very high fired film densities and smooth surface finishes result in excellent performance at microwave frequencies. Transmission characteristics at frequencies up to 4 GHz compare favorably to sputtered thin film gold and copper. Characterization at higher frequencies is underway.

Direct Cooling of Propulsion Drives for High Power Density and Low Volume

Abstract: : This final report summarizes the research work and conclusions related to ONR Award N00014-01-1-0634 under the DoD DESPCoR Program. The main objective of this grant was to investigate the feasibility of using spray cooling as the thermal management technology for power semiconductor devices used in power converter applications. this report covers the following: Basics of spray cooling, a novel power packaging methodology for power semiconductor devices that is compatible with spray cooling, the design of a power module serving as a technology demonstrator, and laboratory experimental results. Initial results seems to be superior to other approaches like cold-plate cooling.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

A Survey of Wide Bandgap Power Semiconductor Devices

Abstract: Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC- and GaN-based power semiconductor devices together with an overall view of the state of the art of this new device generation.

Overview of Dual-Active-Bridge Isolated Bidirectional DC–DC Converter for High-Frequency-Link Power-Conversion System

Abstract: High-frequency-link (HFL) power conversion systems (PCSs) are attracting more and more attentions in academia and industry for high power density, reduced weight, and low noise without compromising efficiency, cost, and reliability. In HFL PCSs, dual-active-bridge (DAB) isolated bidirectional dc-dc converter (IBDC) serves as the core circuit. This paper gives an overview of DAB-IBDC for HFL PCSs. First, the research necessity and development history are introduced. Second, the research subjects about basic characterization, control strategy, soft-switching solution and variant, as well as hardware design and optimization are reviewed and analyzed. On this basis, several typical application schemes of DAB-IBDC for HPL PCSs are presented in a worldwide scope. Finally, design recommendations and future trends are presented. As the core circuit of HFL PCSs, DAB-IBDC has wide prospects. The large-scale practical application of DAB-IBDC for HFL PCSs is expected with the recent advances in solid-state semiconductors, magnetic and capacitive materials, and microelectronic technologies.

Eliminate Reactive Power and Increase System Efficiency of Isolated Bidirectional Dual-Active-Bridge DC–DC Converters Using Novel Dual-Phase-Shift Control

Abstract: This paper proposes a novel dual-phase-shift (DPS) control strategy for a dual-active-bridge isolated bidirectional DC-DC converter. The proposed DPS control consists of a phase shift between the primary and secondary voltages of the isolation transformer, and a phase shift between the gate signals of the diagonal switches of each H-bridge. Simulation on a 600-V/5-kW prototype shows that the DPS control has excellent dynamic and static performance compared to the traditional phase-shift control (single phase shift). In this paper, the concept of ldquoreactive powerrdquo is defined, and the corresponding equations are derived for isolated bidirectional DC-DC converters. It is shown that the reactive power in traditional phase-shift control is inherent, and is the main factor contributing to large peak current and large system loss. The DPS control can eliminate reactive power in isolated bidirectional DC-DC converters. In addition, the DPS control can decrease the peak inrush current and steady-state current, improve system efficiency, increase system power capability (by 33%), and minimize the output capacitance as compared to the traditional phase-shift control. The soft-switching range and the influence of short-time-scale factors, such as deadband and system-level safe operation area, are also discussed in detail. Under certain operation conditions, deadband compensation can be implemented easily in the DPS control without a current sensor.

Wearable Electrochemical Sensors and Biosensors: A Review

Abstract: This article reviews recent advances and developments in the field of wearable sensors with emphasis on a subclass of these devices that are able to perform highly-sensitive electrochemical analysis Recent insights into novel fabrication methodologies and electrochemical techniques have resulted in the demonstration of chemical sensors able to augment conventional physical measurements (ie heart rate, EEG, ECG, etc), thereby providing added dimensions of rich, analytical information to the wearer in a timely manner Wearable electrochemical sensors have been integrated onto both textile materials and directly on the epidermis for various monitoring applications owing to their unique ability to process chemical analytes in a non-invasive and non-obtrusive fashion In this manner, multi-analyte detection can easily be performed, in real time, in order to ascertain the overall physiological health of the wearer or to identify potential offenders in their environment Of profound importance is the development of an understanding of the impact of mechanical strain on textile- and epidermal (tattoo)-based sensors and their failure mechanisms as well as the compatibility of the substrate employed in the fabrication process We conclude this review with a retrospective outlook of the field and identify potential implications of this new sensing paradigm in the healthcare, fitness, security, and environmental monitoring domains With continued innovation and detailed attention to core challenges, it is expected that wearable electrochemical sensors will play a pivotal role in the emergent body sensor networks arena