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We investigate both experimentally and numerically the transformation of spatial coherence function (SCF) during reflection from a scattering medium. We demonstrate that the information about SCF of the incident field survives scattering at grazing angles of incidence and for angularly detuned observation direction.
An ultra-wideband absorber based on employing multiple resonators in the unit cell of a 3-D frequency-selective structure is proposed. The original design consists of two-dimensional periodic array of three-dimensional unit cells and lumped components to provide matching with free space and absorb the incident electromagnetic wave. By introducing one more resonator in the unit cell, an ultra-wideband...
This paper presents a circular polarization converter based on an array of planar helices, which can effectively reject the left-hand circularly polarized (LCP) incident wave, while convert the right-hand circularly polarized (RCP) incident wave into an outgoing LCP wave. The proposed converter features a broad operation bandwidth with high rejection for LCP incident wave and high conversion coefficient...
A wideband polarization rotator based on frequency selective surfaces is presented in the paper. The rotator is constructed by a two-dimensional periodic array of substrate integrated waveguide cavities, with two twisted slots etched on the front and back surfaces, respectively. The wave is coupled into and out of the cavity with its polarization direction rotated. Our work demonstrates the effectiveness...
This paper presents the design and evaluation of a two-switch flyback power supply with ultra-wide input voltage range (230–1300 V), fed from the floating dc bus of power electronics building blocks (PEBB) in medium voltage (MV) modular multilevel converter (MMC) applications. Rated at 80 W, 48 V output, and operating at 50 kHz, the proposed converter uses 1.7 kV SiC devices and a planar PCB-winding...
The (n, k)-star graph is a generalization of the star graph. We first present an optimal neighbourhood broadcasting algorithm for the (n, k)-star, which is then used to develop an optimal broadcasting algorithm for it. Both algorithms are for the single-port model of the network. While our neighbourhood broadcasting is the first such algorithm designed for the network, our optimal O(log(n!/(n − k)!))-time...
The ferromagnetic resonance frequency fFMR of soft magnetic films (SMFs) can be expressed by the Kittel equation. Clearly, high 4pMS and HK are needed to achieve a high fFMR in SMFs. Previous research on achieving high fFMR SMFs has mostly been focused on enhancing uniaxial magnetic anisotropy field HK since it is relatively easier to be enhanced by 1–2 orders of magnitude, compared to saturation...
This paper proposes an operation optimization model for micro-turbine based Combined Cooling, Heating and Power(CCHP) systems. The proposed model is adopted to analyze CCHP systems to minimize the operating cost, and takes accounts of the electricity pricing method and interactive mode with the network. Under spot price, the economy of the CCHP system is analyzed and compared with a decentralized...
In recent years, indoor positioning systems have become important and WiFi positioning based on fingerprinting has been gaining a lot of attention in this field. However, surveying for the WiFi fingerprints in a specific area is a labor and time consuming process. In this work, an innovative method is proposed to automatically generate geo-referenced radio maps for Wireless Local Area Networks (WLAN)...
Micro-simulation becomes more and more important in the Intelligent Transportation Systems (ITS) research, because it can provide detailed descriptions of the system. For a multi-agent systems (MAS) modeling of an ITS, the computation burden is large, as it involves the computation of the state changing of all the agents. And, there are many multi-objective optimization problems in the ITS research...
In this paper, a long slot antenna of conical radiation beam is presented, which is based on the substrate integrated waveguide (SIW). The antenna consists of a pair of tapered long slots etched out of both the top and bottom broad walls of a substrate integrated waveguide to produce the conical radiation beam. Experiment results of the fabricated antenna show that the realized beam-pointing angle...
As the computing technology develops, micro-simulation becomes more and more important in the Intelligent Transportation Systems (ITS) research, because it can provide detailed descriptions of the system. However, for a multi-agent systems (MAS) modelling of an ITS, the computation burden is large, as it involves the computation of the state changing of all the agents. Further, if we consider simulation...
In designing frequency selective surfaces (FSS), one of the desirable design goals is to achieve a wide bandwidth, as well as a sharp transition from pass- to stop-band. There are several techniques used to control the FSS bandwidth, which include: (i) choosing suitable lattice spacing; (ii) using element shapes that provide a sharp frequency transition, e.g., screens with thick apertures; and (iii)...
With the development of enabling power electronic devices, such as the solid state transformer (SST) [1], the concept of a novel future renewable electric energy delivery and management system [2] is raised. The Future Renewable Electric Energy Delivery and Management (FREEDM) system is a smart distribution system that can accommodate distributed renewable energy, distributed energy storage devices,...
This paper investigates the impact of wavelength/waveband convertors in hierarchical optical path networks. It shows that even if their costs are relatively high, hierarchical optical path networks can be cost effective over a wide traffic demand area.
In an effort to improve the situational awareness of maritime vehicles, flexible MEMS pressure sensor arrays are developed for underwater sensing applications. This paper outlines the development of piezoelectric microdiaphragm pressure sensor arrays that can perform a passive fish-like underwater sensing. Individual sensors have a low footprint of 1.8 × 1.8 mm2 and do not require any power for their...
This paper presents a finite macro-element method based on a new macro basis function constructed from the modal solutions of Helmholtz equation. Different from existing basis functions, the proposed macro basis function satisfies Helmholtz equation automatically, and it allows the use of coarse elements. As an example, the proposed method is applied to calculate the cutoff wavenumbers of waveguides,...
Consider the problem of routing from a single source node to multiple target nodes with the additional condition that these disjoint paths be the shortest. This problem is harder than the standard one-to-many routing in that such paths do not always exist. Various sufficient and necessary conditions have been found to determine when such paths exist for some interconnection networks. And when these...
The paper reports the fabrication, characterization, and experimental results of a piezoelectric MEMS pressure sensor array for underwater sensing applications. An array of five PZT sensors is developed that can perform passive fish-like underwater sensing. The array is capable of locating underwater objects by transducing the pressure variations generated by moving objects. Individual sensors have...
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