Lossless Multiway Power Combining and Outphasing for High-Frequency Resonant Inverters

A lossless multi-way power combining and outphasing system have recently been proposed for high-frequency inverters and power amplifiers that offers major performance advantages over traditional approaches. This paper presents outphasing control strategies for the proposed power combining system that enable output power control through effective load modulation of the inverters. It describes a straightforward power combiner design methodology and enumerates various possible topological combiner implementations. Moreover, this study presents the first-ever experimental demonstration of the proposed outphasing system. The design of a 27.12 MHz, four-way power combining and outphasing system is described and used to experimentally verify the power combiner's characteristics. The proposed outphasing law is shown to be effective in controlling the output power over a 10-100 W (10:1) power range

Design of Single-Switch Inverters for Variable Resistance/Load Modulation Operation

Single-Switch inverters such as the conventional Class-E inverter are often highly load sensitive, and maintain zero-voltage switching over only a narrow range of load resistances. This paper introduces a design methodology that enables rapid synthesis of Class E and related single-switch inverters that maintain ZVS operation over a wide range of resistive loads. We treat the design of Class-E inverters for variable resistance operation and show how the proposed methodology relates to circuit transformations on traditional Class-E designs. We also illustrate the use of this transformation approach to realize Φ[subscript 2] inverters for variable-resistance operation. The proposed methodology is demonstrated and experimentally validated at 27.12 MHz in a Class E and Φ[subscript 2] inverter designs that operate efficiently over 12:1 load resistance range for an 8:1 and 10:1 variation in output power, respectively, and a 25-W peak output power.Massachusetts Institute of Technology. Center for Integrated Circuits and SystemsMIT Energy InitiativeSkolkovo Institute of Science and TechnologyWarsaw University of Science and Technology (Poland). Center for Advanced Studie

INFLUENCE OF LAYER ARRANGEMENT ON THE STABILITY AND FAILURE OF THIN-WALLED COMPOSITE STRUCTURES

The purpose of this article is to study the effect of the layup n stability and load carrying capacity of a thin-walled composite structure with an open section - angle. The research part carried out by means of the finite element method, using the commercial software Abaqus®, presents the analysis of the limit states of compressed composite profiles, made of carbon-epoxy (CFRP) material, with a variable layer configuration

Electrically conductive PTT-block-PTMO/SWCNTs+Graphene Nanoplatelets hybrid nanocomposites prepared by in situ polymerization

Hybrid Materials 2015; Sitges, Barcelona, Spain, 9 - 13 March 2015The studies were financed by the National Science Centre within project PRELUDE no 2013/11/N/ST8/00404.Peer Reviewe

Recreational Development at Pelican Lake, Minnesota: An Analysis of Factors Affecting Site Selection

In order to better predict those areas whicd\u27 have the po tential to be developed more rapidly than others, research concerning physical land use character isti ;s which determine current lakeshore patterns needs to be implemented. This study is designed to assess which physics . land use/cover characteristics have affected lake home development at Peli can Lake in north central Minnesota. Analysis involves the interpretation of aerial photo graphs from the years 1939, I960, 1969, and 1978 which were used to map location and extent of land use/cover change in the Pelican Lake area. Archival data is utilized in order to determine number and location of recreational homes ex isting on the shoreline of Pelican Lake. Finally, correla tion and regression techniques are used in order to ascer tain relationships between the physical parameters of the watershed and location of lakeshore homes. Length of shoreline is found to be the leading indicator in number of homes in each section bordering Pelican Lake. Distance to nearest improved road also proves to be a sig nificant factor. Of the land use/cover data obtained from aerial photographs, only acres of that land covered by water and.acres in Pelican. Lake are determined to be of signifi cance in location of lakeshore homes

Broadband dielectric spectroscopy of nanocomposites based on PVDF and expended graphite

2nd International Conference on Structural Nano Composites (NANOSTRUC 2014); 6 pags.; 4 figs.; Open Access funded by Creative Commons Attribution 3.0 licence.Nanocomposites based on poly (vinylidene fluoride) (PVDF) and expanded graphite (EG) were prepared by non-solvent precipitation from solution with different EG concentrations. Films were obtained by compression molding and their structural and dielectric properties studied. From Wide Angle X-ray Scattering (WAXS) experiments, it can be assessed that for all EG concentrations the -crystalline phase of PVDF is the predominant crystalline form. However, for composites with high nanoadditive content, higher than 3 wt.%, the -crystalline phase is also detected. Dielectric spectroscopy results showed that the nanocomposites present both high dielectric constant and electrical conductivity at low percolation threshold. Published under licence by IOP Publishing LtdThe authors thank the financial support from the Spanish Ministry of Science and Innovation (MICINN), Grant MAT2012-33517 and from the Polish National Science Centre and the Slovak Academy of Sciences in the frame of ERA-NET project APGRAPHEL.Peer Reviewe

Formation of LIPSS in nanocomposites of poly(ethylene terephthalate)/expanded graphite by using UV nanosecond laser pulses

Frontiers in Optics: The 100th OSA Annual Meeting and Exhibit/Laser Science XXXII; Rochester, New York United States; 17 Oct 2016 - 21 Oct 2016; http://www.frontiersinoptics.orgPeer Reviewe

LIPSS formation by nanosecond laser irradiation of Poly(ethylene terephthalate) and Poly(trimethylene terephthalate) reinforced with carbon-based fillers

XII Jornadas de Procesado de Materiales con Láser AIMEN; O Porriño (Pontevedra); 29 y 30 de septiembre de 2016The formation of Laser Induced Periodic Surface Structures (LIPSS) is a process commonly used to nanostructure polymer surfaces. Forming of LIPSS is possible because of the irradiation of the polymer surface with polarized laser pulses at fluences below the ablation threshold. This leads to a modulation of the depth of the surface, resulting from an inhomogeneous intensity distribution, due to the interference between the incoming and the surface-scattered waves, reinforced with a positive feedback process. Such structures have a spatial period close to the laser wavelength, aligned parallel to the polarization of the laser beamPeer Reviewe