ACES Publication Search





There are 32 search results for:



Title: ACES Journal October 2018 Cover
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2165 KB

Title: ACES Journal October 2018 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 848 KB

Title: ACES Journal October 2018 Full
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 20304 KB

Title: Low Rank Matrix Algebra for the Method of Moments
Abstract: This tutorial presents the use of low rank Rk matrix block formulations for advancing the problem size capability N of the Method of Moments full wave approach to solving Maxwell’s integral equations. When MOM unknowns are spatially grouped, the group-group interaction matrix blocks become low rank for electrically large problems. A very significant advantage of this Rk property along with use of the Adaptive Cross Approximation leads to dramatic reduction in memory storage and in operations count. While early Rk approaches focused on iterative approaches, this work shows how Rk methods can be applied to direct solve LU factorization approaches and, for scattering problems, Rk methods can be used to compute the full polarization scattering matrix.
Author(s): J. Shaeffer
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2029 KB

Title: A Nystrom Discretization of a Broad-Band Augmented-Müller Surface Integral Equation
Abstract: A broad-band Augmented-Muller (AMuller) surface integral equation method for scattering from material objects is presented. The formulation incorporates surface electric and magnetic charges into the conventional Muller formulation with added constraints on the normal magnetic and electric fields. A new technique to extract the static fields is introduced which improves accuracy of computing scattered near fields at very low frequencies. The (A-Muller) formulation is discretized using the locally corrected Nystrom (LCN) method. Numerical results show that the method is high-order accurate and stable over a broad frequency range from arbitrarily low to high frequencies for simply connected, multiply connected, highly lossy, high contrast and complex material geometries. The proposed formulation does not incorporate line charges, charge continuity constraints, or any frequency scaling of the degrees of freedom.
Author(s): N. Hendijani, S. D. Gedney, J. C. Young, R. J. Adam
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2912 KB

Title: Provably Stable Local Application of Crank-Nicolson Time Integration to the FDTD Method with Nonuniform Gridding and Subgridding
Abstract: This contribution removes some doubts about the stability issues associated with the local and anisotropic use of Crank-Nicolson (CN) time integration in Finite-Difference Time- Domain (FDTD) simulations with spatial irregularities such as nonuniformity and subgridding.
Author(s): A. Van Londersele, D. De Zutter, D. Vande Ginste
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1419 KB

Title: FEKO™ Modeling Study of Passive UHF RFID Tags Embedded in Pavement
Abstract: Radio frequency identification (RFID) is investigated as a technology that may be useful for smart cars and autonomous vehicles to read information about local road conditions and geographic location. Passive UHF RFID tags can transmit this data wirelessly to an RFID reader mounted on the vehicle. Coupling between a tag that is on or embedded in pavement, and the reader antenna mounted on the vehicles, is investigated by simulating the tag antenna, reader antenna and local environment in FEKO™. Preliminary simulation results show that it is feasible to implement such a system such that a vehicle traveling up to 200 km/hr. can read the tags as it passes over them.
Author(s): S. R. Walvekar, R. J. Burkholder
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1586 KB

Title: High-Order Moment-Matching MOR with Impedance Boundaries for Signal Integrity Analysis
Abstract: This paper presents an extension of highorder moment-matching model order reduction to frequencydependent impedance boundary conditions. Such boundary conditions are essential for accurately and efficiently modeling conductors at high frequency, where skin effect is significant. These boundary conditions involve complicated transcendental functions, whereas previous MOR methods assume polynomial dependence. Automatic differentiation is used to easily and accurately calculate the higher derivatives of such functions. Substantial improvement is shown, not only compared to discrete frequency sweeps, but also compared to non-momentmatching S matrix interpolation.
Author(s): M. B. Stephans
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1568 KB

Title: Whistler Mode Wave Refractive Index in a Finite Temperature Anisotropic Plasma Medium
Abstract: Whistler mode waves, which exist in a magnetized plasma, are prevalent in the Earth's magnetosphere in the extremely low frequency (ELF) and very low frequency (VLF) bands (100 Hz - 30 kHz). Due to the impact of whistler mode waves on space weather processes, it is important to accurately predict the propagation trajectory of these waves and their properties. Numerical raytracing determines the power flow path of the whistler mode waves in the anisotropic medium of the magnetosphere based on local calculation of the refractive index. In the majority of previous work, magnetospheric raytracing has been implemented assuming a cold background plasma (0 K). However, a more accurate description of the magnetospheric plasma includes a background temperature of about 1 eV (11600 K). We present solutions to the dispersion relation that include the effects of finite electron and ion temperatures on the wave refractive index using a warm plasma formulation. Finite temperature effects of the background plasma are shown to be most significant for highly oblique wave normal angles where the refractive index is bounded to smaller values than in the ideal cold plasma approximation.
Author(s): M. Golkowski, A. Maxworth
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1848 KB

Title: Locally Corrected Nystrom Discretization for Impressed Current Cathodic Protection Systems
Abstract: A high-order locally corrected Nystrom discretization for analyzing impressed current cathodic protection systems is presented. Non-linear polarization curves are incorporated using a Newton-Raphson scheme. A Schur complement scheme is introduced to handle large domains with small electrodes. The methods are characterized in terms of error convergence and computation time by comparing to the analytic solution for a sphere and hemisphere.
Author(s): J. C. Young, R. A. Pfeiffer, R. J. Adams, S. D. Gedney
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1675 KB

Title: "Faster" Could be "Slower": Uncovering the Salient Characteristics of Slow-light Guided Signals with the Finite-Difference-Time-Domain (FDTD) Method
Abstract: Slow-light mesophotonic waveguides have gained increasing interest in the recent years because of their catalyzing potential to transform applications relying on all-optical signal manipulation or enhanced light-matter interactions. The quests in this area have been targeting waveguide platforms with a giant group velocity index as determined by modal type of analyses in frequency domain. We show here that these efforts with frequency-domain methods have entirely missed on important mode features which are nevertheless crucial in practically effecting an ultra-slow guided pulsed signal with a large time delay. We utilize first-principle electromagnetic (EM) simulations in time-domain and show that contrary to conventional wisdom, the group-index by itself is not in general a good measure of the slow-down factor for a pulsed light signal propagating within the waveguide. We present a counterexample comparing two modes which demonstrates that the “faster” mode, the one with the lower group index, is the one that leads to larger effective time delays. The time-domain analysis in this counter-example uncovers a new figure of merit for practical slow-light platforms which indicates that along with a near-zero group velocity, a relatively low group-velocity dispersion value is simultaneously required.
Author(s): S. Foteinopoulou
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1677 KB

Title: A Finite-Difference Frequency Domain Solver for Quasi-TEM Applications
Abstract: A finite-difference frequency-domain (FDFD) solver applicable to quasi-TEM applications is defined. The FDFD solver is applicable to a wide variety of transmission line structures where the cross-sectional dimensions govern the frequency range over which the quasi-TEM approximation is valid. The quasi-TEM FDFD solver provides an efficient solution for conductor current distributions involving both skin effect and proximity effect. Simulation results obtained using the quasi-TEM FDFD solver are compared to measurements and other numerical methods.
Author(s): J. P. Donohoe
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1656 KB

Title: DMD-Galerkin Model Order Reduction for Cardiac Propagation Modeling
Abstract: Numerical simulation of cardiac propagation is a valuable tool for biomedical research. Due to the inhomogeneous, anisotropic conductive anatomy and complex nonlinear ionic current, numerical modeling of electrical activities in the heart is computationally demanding. Here, model order reduction is used to reduce the simulation time with a minimal effect on the accuracy. The semi-implicit finite difference method is used to discretize the governing equation of the monodomain (reaction-diffusion) model. The dynamic mode decomposition (DMD) is used in combination with the Galerkin projection to reduce the order of the original system. The reduced-order model is obtained by projecting the original system onto a subspace spanned by DMD basis vectors. Numerical results confirm the model order reduction decreases the simulation time by a factor of 5.96 while modifying the computed activation time, maximum time derivative and conduction velocity by 1.24%, 0.129%, and 0.639%, respectively.
Author(s): R. Khan, K. T. Ng
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1727 KB

Title: Efficient Adaptive Qualitative Methods for 3D Inverse Scattering Problems
Abstract: In this paper we extend our recently developed 2D adaptive factorization method for efficiently solving 3D inverse acoustic and electromagnetic scattering problems. Different from the previously used Simpson rule, we propose to use Gaussian quadrature rule, which provides improved reconstruction quality. Several numerical examples are presented to illustrate the effectiveness of our proposed adaptive method. To achieve better efficiency and robustness, we have based our implementation on the existing adaptive quadrature codes.
Author(s): K. H. Leem, J. Liu, G. Pelekanos
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2718 KB

Title: Enabling Batteryless Wearables and Implants
Abstract: Powering of wearables and implants is a critical challenge. Conventional batteries are rigid and require frequent recharging and/or replacement, making their use cumbersome and obtrusive for body-area applications. Instead, this paper discusses three novel technologies that our group has recently explored toward batteryless wearables and implants, viz. a) DC power generation using fabric electrochemistry, b) Radio-Frequency (RF) power harvesting, and c) fully-passive RF backscattering. Notably, the proposed technologies bring forward transformational possibilities for batteryless sensing and/or stimulation.
Author(s): W.-C. Chen, B. DeLong, R. Vilkhu, A. Kiourti
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1527 KB

Title: Circuitry Design and Magnetic Susceptibility Evaluation of 7T fMRI Implantable RF Coil
Abstract: Implantable coils have been widely utilized in functional magnetic resonance imaging (fMRI) owing to their superior signal to noise ratio. To effectively minimize the magnetic field distortion and image artifacts, the magnetic susceptibility of the implantable coil needs to be evaluated before practical use. In this work, we experimentally identify the magnetic susceptibility of each component of the implantable coil with the 7T Bruker NMR imaging scanner and provide useful guidelines for the following manufacturing. A 5 x 5 mm2 implantable surface coil with a tunable frequency range is subsequently introduced for the 7T fMRI of the rat primary somatosensory cortex (S1FL). A detachable external tuning circuit for the implantable coil is employed to facilitate in-vivo measurements in the rat model.
Author(s): R. Wang, C. M. Dong, E. X. Wu, R. C. Roberts, L. J. Jiang
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1636 KB

Title: Theoretical Study of Different Access Points in coupled Wireless Power Transfer – Powerline Communication Systems
Abstract: In this contribution the authors investigate the possibility of improving the performances of a coupled Wireless Power Transfer (WPT) - Power Line Communications (PLC) system in case the WPT system is characterised by a four coils structure. The main idea is to use the so-called transmitting and receiving coil (the two "inner" coils) as access point for the PLC modems and use the drive and load loops (the two "outer" coils) as usual access point for power transfer. The simulations results show that a wider band for communication is achieved with respect the previously proposed system.
Author(s): S. Barmada, M. Tucci
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2058 KB

Title: A Six-Elements Circularly Polarized Sequential Array for Dedicated Short Range Communications in C-band
Abstract: In this paper an antenna array operating in circular polarization in the C-band is presented. The array is based on the sequential rotation architecture, applied to six elements, and arranged in hexagonal shape. Thanks to its geometry, the array is suitable for tiling of surfaces as well as for regular solid arrangement. Satisfying experimental validation of a prototype based on the proposed design is observed, with a peak gain of 10.4 dB at 5.8 GHz maintained within 3 dB over a 500 MHz band, a 10 dB return loss bandwidth of 500 MHz, and a 3dB axial ratio bandwidth of almost 400 MHz, meaning 6.5% of fractional bandwidth.
Author(s): L. Berretti, S. Maddio, G. Pelosi, M. Righini, S. Selleri
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2444 KB

Title: A Quad-Band Antenna with AMC Reflector for WLAN and WiMAX Applications
Abstract: This letter presents a quad-band antenna with high gain for wireless local area network (WLAN) and Worldwide Interoperability for Microwave Access (WiMAX) communication covering the IEEE 802.11a/b and IEEE802.16d/e standards. The antenna consists of a microstrip feed line with a complementary microstrip-slot pair and a secondary slot element on a single dielectric medium. A single-band artificial magnetic conductor (AMC) surface was used as a reflector to achieve a unidirectional radiation pattern with an average gain of 9.3 dBi. The antenna was optimized to achieve a radiation efficiency of more than 90% in the WLAN and WiMAX frequency bands. The size of the antenna with the AMC reflector is 80×80×10 mm3. The radiation properties of the antenna were measured in a compact antenna range and simulated and measured results are presented.
Author(s): E. W. Coetzee, J. W. Odendaal, J. Joubert
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2116 KB

Title: A Wideband Antenna for Biotelemetry Applications: Design and Transmission Link Evaluation
Abstract: In this paper, the design of a miniature wideband antenna for biotelemetry applications is presented. We propose a biocompatible antenna to be printed on the outer surface of a capsule. The size of the antenna in planar form is 2.52 mm3. The antenna shows a wide impedance bandwidth of 7.31 GHz (0.78 GHz – 8 GHz, for -10dB reflection coefficient) when implanted inside a simple three layer body model. The antenna gain values at 915 MHz and 2.45 GHz are -25.23 dBi and -27.51 dBi, respectively. The antenna resonance frequency is shown to be robust when implanted in a realistic anatomical body model. The performance of the communication link between the implanted antenna and an external half-wavelength dipole at 915 MHz and 2.45 GHz is also presented.
Author(s): A. Alemaryeen, S. Noghanian
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1715 KB

Title: Design and Implementation of a Quad Element Patch Antenna at 5.8 GHz
Abstract: This paper presents simulation and experimental verification of a quad microstrip patch antenna that operates at 5.8 GHz. Sonnet antenna design software was used to simulate the performance of the antenna. To reduce the design’s complexity and the computational load, the antenna and the feeding lines were simulated separately. An optimization was done for each subpart to get the optimum desired results. Finally, all the subparts were merged and the final structure was simulated to check the performance. A prototype of the antenna was fabricated on a double-sided PCB substrate (relative permittivity=10.2, thickness=1.28 mm) using a PCB milling machine. The S11 of -14 dB and -18.8 dB and maximum gain of 6.2 dB and 4.2 dB were obtained, from the simulation and experimental measurements, respectively.
Author(s): M. R. Sobhani, N. Majidi, S. T. Imeci
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1809 KB

Title: Design and Comparison of 4 Types of Dual Resonance Proximity Coupled Microstrip Patch Antennas
Abstract: In this paper there are four different shapes of proximity patch antennas (straight, trimmed, trapezoid and ribbon). The minimum input match achieved with the straight proximity patch antenna as -39.68 dB. The maximum gain is achieved with the ribbon proximity patch antenna as 12.1 dB. Simulation and measurement results are presented. There is a perfect match with simulated and measured gain. The antenna is first demonstrated example of working with four different geometries, having satisfactory gain and input match.
Author(s): N. Majidi, M. R. Sobhani, B. Kilic, M. Imec, O. S. Gungor, S. T. Imeci
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1763 KB

Title: Supercapacitor Implementation for PV Power Generation System and Integration
Abstract: Novel hybrid energy storage system configuration is introduced by interleaving the supercapacitor between the electrostatically sensitive devices (ESDs) and DC-link capacitors that can handle all power demands in transient or steady state conditions, and perform the ESD functions. The new system integrates an adaptive sliding-mode DC-DC control method to address the voltage permutations and ensure the required output voltage. Bi-directional power flow, important to the continuous hybrid energy storage system operation is also fulfilled. The continuous successful operation is provided with supplemental protection controls. The operation of the proposed system is verified through simulation with Matlab/Simulink. The hybrid energy system developed in this paper can be used in several applications including electrical vehicles and grid integration of Photovoltaic (PV) systems.
Author(s): A. Eroglu, T. Dey, K. Dey, G. Whelan
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1728 KB

Title: Design and Study of a Small Implantable Antenna Design for Blood Glucose Monitoring
Abstract: In this paper, a miniaturized implantable antenna with the dimensions of 8×8×1 mm3 has been studied for continuous monitoring of Blood Glucose Levels (BGL). The antenna performance is analyzed numerically for both the free space and implanted operation. The results show that the works excellently in both the scenarios. The antenna has the lowest resonant frequency of 3.58 GHz in free space with a gain 1.18 GHz while it operates at 2.58 GHz with a gain of 4.18 dBi. Good performance, small size and resilience to the human body effects make the antenna to have a good potential use in future implantable glucose monitoring devices.
Author(s): A. Ahmed, T. Kalsoom, M. Ur-Rehman, N. Ramzan, S. Karim, Q. H. Abbasi
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1983 KB

Title: A Cost-Effective Far-Field Antenna Pattern Measurement System
Abstract: A low-cost far-field antenna measurement solution is developed and presented. In an increasingly wireless society, it is important to be able to characterize antennas. Unfortunately, determining antenna radiation pattern characteristics is an involved and often expensive process. The presented system provides a complete combination of hardware and software that can be used for far-field pattern measurements of an antenna operating in the 700 MHz to 18 GHz range. This would allow institutions and groups with few resources to be able to characterize the radiation pattern of antennas for many emerging applications.
Author(s): K. Patel, R. Jones, A. Elsherbeni
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1804 KB

Title: Reduction of Coupling between Flush-Mounted Antennas
Abstract: This paper discusses some numerical aspects of the coupling study between two flush-mounted antennas. It is shown that a bed of nails embedded between flush-mounted quad-ridge horns separated by 20 cm (4 lambda 6 GHz) edge-to-edge greatly reduces coupling by about 17 dB at lower frequency end, where the electrical distance between antennas is the shortest. The considered antenna system operates from 6-19 GHz and has |S11| < -10 dB, and coupling < -60 dB. The numerical modelling is carried out using MoM and FEM solvers. The computed results are in good agreement with measurements.
Author(s): P. V. Prasannakumar, M. A. Elmansouri, M. Ignatenko, D. Filipovic
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1853 KB

Title: Full-Wave Modeling of RF Exciters Using WIPL-D: Road to Real-Time Simulation and Optimization
Abstract: Computational tools for full-wave three-dimensional (3-D) simulations of linear passive electromagnetic (EM) components have reached a point where they became both practical and necessary in computer aided design (CAD) of RF devices. Although circuit-based solvers still offer unprecedented speed and true real-time tuning, full-wave software tools, which take into account almost all physical EM phenomena, rapidly approach similar efficiency and applicability. This, however, is not possible by just using modern hardware environment, but it also requires the numerical method of choice, encapsulated within a software tool, to be extremely precise and conservative in consumption of computer resources, i.e., CPU and memory. We here report a case study which demonstrates highly efficient utilization of higher order large-domain method of moments (MoM) modeling and optimization using WIPL-D. The example includes an RF exciter, based on axial-mode helical antennas mounted on a dielectric support, designed for utilization in the state-of-the-art pre-clinical magnetic resonance imaging (MRI) scanners.
Author(s): P. S. Athalye, M. M. Ilic , B. M. Notaros
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1642 KB

Title: Nonlinear Neural Network Equalizer for Metro Optical Fiber Communication Systems
Abstract: We present a neural network-based nonlinear electronic feed-forward equalizer. It compensates for the chromatic dispersion (CD) distortions in fiber optic communication systems with direct photo-detection. The proposed equalizer achieves bit error rate (BER) performance comparable to the maximum-likelihood sequence estimator (MLSE), with significantly lower computational cost. The complexity of the introduced equalizer scales linearly with the length of the intersymbol interference (ISI) as opposed to exponential growth the MLSE complexity.
Author(s): M. M. T. Maghrabi, S. Kumar, M. H. Bakr
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1633 KB

Title: Synthesis of NFC Antenna Structure under Multi-Card Condition
Abstract: Wireless communication technologies such as Near Field Communication (NFC) found its way into our everyday life. The antenna structures used in such systems have to comply with several standards to achieve all requirements defined for the specific application. However, in practice there are scenarios for such antennas which are not considered in standards or design guides, but mainly influence the antenna behavior. In the present paper the synthesis of an antenna used for NFC-cards in a contactless payment system under multi-card condition is presented. The optimization relies on the differential evolution (DE) strategy. The computation of the forward problem is based on the partial element equivalent circuit (PEEC) method.
Author(s): P. Baumgartner, T. Bauernfeind, O. Biro, C. Magele, W. Renhart, R. Torchio
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1593 KB

Title: A Low Complexity GNSS Array Signal Angle of Arrival (AoA) Estimation Algorithm and Validation
Abstract: Adaptive antenna array techniques are widely utilized to reject multipath and interference errors in Global Navigation Satellite System receivers (GNSS). Several methods have been proposed to tackle this issue. However, one severe problem for existing methods is the implementation complexity as GNSS receivers usually work under a high-dynamic receiving environment, thus may have the requirement of rapid angle estimates. In this paper, we propose a low complexity GNSS array signal estimation algorithm. Live data validation shows that the estimated AoA values can be used to improve the Carrier-to-Noise-Ratio by 1~4 dB-Hz.
Author(s): B. Wang, Y. Li, N. C. Shivaramaiah, D. M. Akos
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2704 KB

Title: Power Transfer Efficiency for Distance-Adaptive Wireless Power Transfer System
Abstract: In this paper, a highly efficient distance-adaptive wireless power transfer system with automatic impedance tuning control at variable distances is proposed, and we compare the power transfer efficiency of wireless power transfer system at different operating conditions using the method of moments (MoM) technique. By sensing a reflected power and controlling impedance tuning networks, the proposed wireless power transfer system achieves the high and stable efficiency with regard to the variable operating distances. According to adaptive impedance matching algorithms under the minimum reflected power conditions, the proposed system achieves an improved power transfer efficiency of approximately maximum 160% within the operating distance.
Author(s): D.-G. Seo, S.-H. Ahn, J.-H. Kim, S.-T. Khang, S.-C. Chae, J.-W. Yu, W.-S. Lee
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 1639 KB

Title: Printed Cross-Slot Wideband Conformal Antenna for GPS Application
Abstract: A novel cross-slot printed wideband conformal antenna is proposed for GPS application. Initially a planar antenna with cross-slot is designed at a slightly higher frequency and then the planar antenna is transformed to the corresponding cylindrical conformal antenna with the desired radius of curvature. The combination of partial ground plane and cross-slot on patch are used for bandwidth enhancement. The proposed conformal antenna exhibits a fractional bandwidth (for the definition of -10dB) of 79.28% operating from 1091 to 2524 MHz, which is suitable for all GPS bands, GLONASS and GALILEO applications. The radiation pattern exhibits an omnidirectional pattern and gain of proposed conformal antenna is 2.37 to 5.33dBi within operating frequency range.
Author(s): R. Sahoo, D. Vakula, N. Sarma
File Type: Journal Paper
Issue:Volume: 33      Number: 10      Year: 2018
Download Link:Click here to download PDF     File Size: 2459 KB