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There is considerable interest in exploiting metamaterials to engineer dispersion relations for new beam/wave interactions that are not possible using conventional all-metal periodic structures. In this paper, we describe the computational design, and both calculated and experimental cold and hot tests of a new high-power microwave slow wave structure at the University of New Mexico to generate a...
Large periodic structures in computational electromagnetics need the management of large number of unknowns, implying high memory use and computation time. Apart from fast techniques such as the multilevel fast multipole algorithm, this kind of problems might be accelerated taking advantage of periodicity properties. We will present some techniques based on the application of the FFT to the method...
Use of computational electromagnetics (EM) in the design of radio-frequency integrated-circuit (RFIC) is presented. Computational EM is not only essential, but also inevitable, for RFIC design without it, it is simply not possible to accurately design (or even design) RFICs effectively and timely. Several examples including RFIC band-pass filter and power amplifier designed based on computational...
Recent extensions in the computation of Green's functions for multi-layered media and half-space problems are reported. For anisotropic problems, a two-level asymptotic singularity extraction is combined with extended Sommerfeld-related identities and the weighted average approach to provide additional acceleration and smoothing of Sommerfeld integrals for efficient simplex interpolation. For lossy...
This work considers a method for including mutual coupling in the characteristic mode analysis (CMA) formulation of finite antenna array elements. The approach applies the domain Green's function method, i.e., a domain decomposition approach based on the method of moments, to extract an active impedance matrix for each array element. These impedance matrices model the active array environment for...
When methods employing auxiliary sources are applied to problems involving scatterers that are circular, it has been shown that convergent and correct fields are obtained by divergent and oscillatory amplitudes (currents) of the sources. In this work, we present some preliminary numerical results, which show that the above conclusions remain valid for non-circular scattering cases.
A synthesis procedure to design passive multiband matching networks for a small non-resonant antenna is presented. Said non-resonant small antenna (12 mm × 3 mm × 2.4 mm) excites efficient modes of a ground plane of a wireless device. Combining the small non-resonant antenna with the synthesis method, a multiband antenna system operating at 824–960 MHz and 1710–2690 MHz is designed to validate the...
A new method to separate anthropogenic noise from natural electromagnetic field measurements is presented in this communication. This new method is based on independent component analysis technique, which allows us to face the problem of separating a measured signal into independent components (ICs) that verify statistical independence. If the signal is the result of the mixture of independent sources...
We compare multi-GPU performance of the multilevel fast multipole algorithm (MLFMA) on two different systems: A shared-memory IBM S822LC workstation with four NVIDIA P100 GPUs, and 16 XK nodes (each is employed with a single NVIDIA K20X GPU) of the Blue Waters supercomputer. MLFMA is implemented for solving scattering problems involving two-dimensional inhomogeneous bodies. Results show that the multi-GPU...
In the proposed study, the effect of gold and magnetic nanoparticles has been analyzed in the presence of low microwave power (1 mW) and small AC magnetic field for hyperthermia application. An analytical study has been carried out on nanoparticles of spherical shape (diameter of 20 nm) dispersed in tissue-equivalent liquid, for which E-field distribution is analyzed for different power levels (maximum...
We propose a new algorithm for real-time implementation of antenna array synthesis and processing using a novel gradient population optimization algorithm implemented on a heterogeneous computing platform which involves dataflow graphs and graphics processing units.
Diffraction phase microscopy maintains the single shot measurement and low speckle noise associated with white light. A microscope with halogen lamp and a Mach-Zehnder interferometer were combined to obtain images of red blood cell with fringe pattern. From these images, the phase values were retrieved by using continuous wavelet transform (CWT) phase method. In the analysis of CWT, Paul wavelet is...
Three-dimensional imaging based on radio frequency that exploits the contrast in dielectric properties of tissues may be used as a low-cost, non-invasive and non-ionizing methodology for breast cancer detection. This paper demonstrates the use of various supervised machine learning algorithms in classification of breast tissues into less-dense fatty and dense fibroglandular or malignant classes from...
In this work, a comparative study on the modehng of periodic structures with commercial full-wave software is performed. In the first method under consideration, only one unit cell of an arbitrary periodic transmission line is analyzed under even/odd excitation. In this method, the coupling between adjacent unit cells is rigorously accounted for. In the second method of analysis, the propagation characteristics...
This paper presents a wearable cylindrical antenna array for microwave brain imaging. The proposed 12-element ultra-wideband array consists of a printed slot antenna with dielectric layer fed with an optimized coplanar waveguide for near-field body matching. The proposed antenna offers ultrawideband performance over the band of 3.13 GHz to 12 GHz where the maximum gain is around 4 dB. The proposed...
The monopolar-Rao-Wilton-Glisson (RWG) discretization of the Poggio-Miller-Chan-Harrington-Wu-Tsai (PM-CHWT) integral equation imposes no continuity constraints in the current expansion across the edges arising from the discretization of the boundary surface. The numerical evaluation of the hypersingular kernel contributions can be carried out through the volumetric testing of the fields over a set...
In the present work, the effects of 650 nm light exposure on the electromagnetic (EM) design of two gain hybrid amplifiers has been investigated. Both amplifiers have been optimized to operate in the 7.5–8.5 GHz frequency band according to the dark parameters of two pseudomorphic high electron mobility transistors having scaled gate widths. In addition, the EM analysis of the effects of the coaxial-to-microstrip...
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