N. Gurler, Y. Ziya Ider
Department of Electrical and Electronics Engineering, Bilkent University, Ankara, Turkey
Designing a Radio Frequency (RF) birdcage coil used in Magnetic Resonance Imaging (MRI) at high frequencies where the wavelength is comparable with the coil dimensions is a challenging task. Before construction of the coil, not only calculating the capacitance value which is necessary for the coil to resonate at the desired frequency but also geometrically modeling the coil in a 3D simulation ...
R. Kumar, P. Singh
Bhabha Atomic Research Center, Trombay, Mumbai, India
High-power couplers working at 350 MHz for particle accelerator cavities are presently under development in the LEHIPA project at BARC. It is important to analyze RF losses on conducting surfaces and resulting thermal profiles. COMSOL Multiphysics® is used to study these coupled RF-thermal effects and estimate cooling requirements for these couplers. The RF loss on the copper conductors and ...
Impedance Matching of Tag Antenna to Maximise RFID Read Ranges & Optimising a Tag Antenna Design for a Particular Application - new
M. Yeoman, M. O'Neill
Continuum Blue Ltd., Ystrad Mynach, UK
Tumbling Dice Ltd., Newcastle, UK
RFID tags are ever increasing in their daily use, from the monitoring of components, the tracking of produce during processing & production, as well as being used in much of the touch-less technologies seen today. With this technology, there has been the ever increasing need to reduce the power required to activate the RFID tag, while maximizing the read range in certain applications. In addition ...
A Design-of-Experiments Approach to FEM Uncertainty Analysis for Optimizing Magnetic Resonance Imaging RF Coil Design - new
J. T. Fong, N. A. Heckert, J. J. Filliben, L. Ma, K. F. Stupic, K. E. Keenan, S. E. Russek
National Institute of Standards & Technology, Gaithersburg, MD, USA
National Institute of Standards & Technology, Boulder, CO, USA
The design of a magnetic resonance imaging (MRI) RF coil using finite element method-based analysis is an essential part of a multi-year research project at the National Institute of Standards and Technology, Gaithersburg, Maryland, where the goal of the project is to develop a “phantom” for calibrating MRI machines that is traceable to standardized values. Traceable MRI calibrations are ...
L. M. Hayden, D. A. Sweigart
Department of Physics, University of Maryland Baltimore County, Baltimore, MD, USA
The generation of terahertz frequency radiation (0.1-10 THz) is an important technological goal due to the use of this non-ionizing radiation to penetrate a wide range of non-conducting materials. One outstanding problem has been the propagation of THz radiation in guided wave devices. Few studies on the construction of efficient THz waveguide devices have been performed. We designed and ...
Hyperbolic Heat Transfer Equation for Radiofrequency Heating: Comparison between Analytical and COMSOL Solutions
V. Romero-García, M. Trujillo, M.J. Rivera, J.A. López Molina, and E.J. Berjano
Centro de Tecnologías Físicas Acústica, Universidad Politécnica de Valencia, Valencia, Spain
Dpto. Matemática Aplicada, Instituto Universitario de Matemática Pura y Aplicada, Universidad Politécnica de Valencia, Valencia, Spain
Institute for Research and Innovation on Bioengineering, Universidad Politécnica de Valencia, Valencia, Spain
The Radiofrequency Heating (RFH) is widely employed to heat biological tissue in different surgical procedures. Most models analyze the RFH employing a Parabolic Heat Transfer Equation (PHTE) based on Fourier's theory. The PHTE can be used for problems involving long heating times or low thermal gradients. However, when the problem involves short heating times or extreme thermal gradients it is ...
J. L. Munoz, and I. Rodriguez
A proton linac drives particles using the electric field of a high power RF standing wave in a resonant cavity. The design of these cavities involve several aspects of multiphysics simulation, that have been accomplished using COMSOL. The first step consist on the geometric optimization of the cavities in order to have the correct frequency while maximizing some figures of merit. This task ...
G. Cerretti, J.-C. Gomez-Lavocat, K. Vynck, D.S. Wiersma
European Laboratory for Non-Linear Spectroscopy (LENS), University of Florence, Sesto Fiorentino, Italy
The Institute of Photonic Sciences (ICFO), Mediterranean Technology Park, Castelldefels, Spain
Istituto Nazionale di Ottica (INO), National Research Council (CNR), Florence, Italy
Liquid-crystal elastomers (LCEs)  have attracted a great attention in recent years due to their high potential in a wide range of applications, from microfluidics components  to artificial muscles . The photo-mechanical response of LCEs is due to their constitutive photo-sensitive molecules, which change shape when absorbing part of the incident light. These microscopic deformations can ...
L. W. Cross, M. J. Almalkawi
Imaging Systems Technology, Toledo, OH, USA
EECS Department, College of Engineering, University of Toledo, Toledo, OH, USA
Large-area, light-weight electromagnetic protection (EP) structures are needed to protect sensitive microwave sensors and communications systems from high-power microwave (HPM) and electromagnetic pulse (EMP) threats. This paper presents the use of COMSOL Multiphysics® for electromagnetic simulation of a plasma-based frequency selective surface (FSS) structure that can provide significant ...
Pryor Knowledge Systems, Bloomfield Hills, MI, USA
The waveguide device modeled here specifically demonstrates the exploration of a small, but very important, subset of components of the family of microwave hardware devices designed to facilitate the optimized transfer of power from the generating source to the consuming load. Each of those components is called, in electronics terminology, a Tuned Stub. A stub is a length of transmission line ...