ACES Publication Search
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| Title: | ACES Journal August 2021 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1789 KB |
| Title: | ACES Journal August 2021 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1047 KB |
| Title: | ACES Journal August 2021 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 19144 KB |
| Title: | A Novel Design of Aperiodic Arrays for Ultrawideband Beam Scanning and Full Polarization Reconfiguration |
| Abstract: | In this letter, a multifunction aperture array is proposed for ultrawideband (UWB) scanning and polarization reconfiguration. The UWB array consisted of linearly polarized elements is capable of operating in four polarization modes (+45° linear polarization (LP), -45° linear polarization, left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP)). This work involves two essential techniques: (a) A new beam-scanning UWB array synthesis approach. An iterative convex optimization strategy is utilized to determine the element locations and obtain the minimum sidelobe level (SLL) for multiple patterns. (b) The polarization reconfigurable technique for beam-scannable arrays. In this part, a sequential rotation and excitation compensation (SR-EC) technique provides polarization reconfiguration for a beam-scannable array consisting of linearly polarized elements. A beam-scanning UWB array is designed by using the proposed UWB array synthesis approach and the SR-EC polarization reconfigurable technique. The Feko numerical result shows 0°-60° beam peak steering, a 4:1 bandwidth (1-4 GHz), and fourpolarization reconfigurability. |
| Author(s): | Z. Zhang, J. Liu, J. Su, J. Song |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2559 KB |
| Title: | Fast Range Decoupling Algorithm for Metamaterial Aperture Real-time Imaging |
| Abstract: | While metamaterial aperture imaging systems do not require mechanical scanning equipment or complex components by employing a spatially variant radiation field, they require large amount of data and many computations. In this paper, we deduce the contribution of the resonator to the radiation fields of the metamaterial aperture. We propose a fast range decoupling algorithm that can improve the data processing speed and obtain real-time images of far-field scenes. The algorithm decomposes the scene into numerous range cells, drastically reduces the range of interest, and reconstructs the scene in parallel. Simulation results show that computational cost is significantly decreased and image quality is maintained. |
| Author(s): | Y. Gao, W. Peng, M. Wang, C. Guo, J. Ding |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2496 KB |
| Title: | Time-dependent Schrödinger Equation based on HO-FDTD Schemes |
| Abstract: | A high order finite-different time-domain methods using Taylor series expansion for solving time-dependent Schrödinger equation has been systematically discussed in this paper. Numerical characteristics have been investigated of the schemes for the Schrödinger equation. Compared with the standard Yee FDTD scheme, the numerical dispersion has been decreased and the convergence has been improved. The general update equations of the methods have been presented for wave function. Numerical results of potential well in one-dimension show that the application of the schemes is more effective than the Yee’s FDTD method and the higher order has the better numerical dispersion characteristics. |
| Author(s): | M. Zhu, F. F. Huo, B. Niu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2167 KB |
| Title: | RK-HO-FDTD Scheme for Solving Time-dependent Schrodinger Equation |
| Abstract: | The Runge-Kutta high-order finite-difference time-domain (RK-HO-FDTD) method is adopted to solve the time-dependent Schrodinger equation. The update equations of the RK-HO-FDTD method have been presented for wave function. The simulation results of the 1D potential well strongly confirm the advantages of the RK-HO-FDTD scheme over the conventional FDTD. |
| Author(s): | M. Zhu, Y. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2193 KB |
| Title: | A Recovery Performance Study of Compressive Sensing Methods on Antenna Array Diagnosis from Near-Field Measurements |
| Abstract: | Antenna testing consists locating the potential defaults from radiated field measurements. It has been established in literature, that compressive sensing methods provide faster results in failure detection from smaller number of measurement data compared to the traditional back-propagation mechanisms. Compressive sensing (CS) methods require a priori measurement of failure-free reference array and require small number of measurements for diagnosis. However, there are conflicting reports in literature regarding the choice of appropriate CS method, and there is no sufficient comparison study to justify which one is a better choice under a very harsh condition. In this study, recovery performance test of CS methods for the diagnosis of antenna array from few near-field measured data under various signal-to-noise ratios (SNRs) is presented. Specifically, we tested three prominent regularization procedures: total variation (TV), mixed l1/ l2 norm, and minimization of the l1 in solving diagnosis problems in antenna array. Linear system that relates the difference between near-field measured data from reference antenna (RA) array and array under test (AUT), and the difference that exist between coefficients of RA and the AUT, is solved by the three compressive sensing regularization methods. Numerical experiment of a 10 × 10 rectangular waveguide array under realistic noise scenario, operating at 10 GHz is used to conduct the test. Minimization l1 technique is more robust to additive data noise. It exhibits better diagnosis at 20 dB and 10 dB SNR, making it a better candidate for noisy measured data as compared to other techniques. |
| Author(s): | O. J. Famoriji, T. Shongwe |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 3718 KB |
| Title: | Performance Investigations of a Quad-band Microstrip Antenna for Body Wearable Wireless Devices |
| Abstract: | This research work proposes a microstripbased quad-band monopole antenna for body Wearable Wireless Devices (WWD) for Wireless Body Area Network (WBAN) applications. Ultra high frequency (UHF) and Ultra wide band (UWB) technology have been known for their efficiency to meet power, size and distance considerations for WBANs. The designed antenna resonates at four frequencies, 1.8, 2.4, 5.0 and 8.9 GHz covering licensed and license-free wireless technologies. The antenna design considers the electromagnetic (EM) effects due to the interaction of body tissues with the radio frequency (RF) waves, which are very different when compared to their interaction with free space. The performance of the antenna is investigated in terms of radiation efficiency, total gain, specific absorption rate (SAR), and thermal effects (short and long term). A simplified, human body tissue layer model is used for simulations utilizing EM computations. Simulated and experimental results are paralleled and are found to be in good agreement. |
| Author(s): | V. Karthik, T. R. Rao |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2359 KB |
| Title: | Design of Compact Reconfigurable Antenna Array for WLAN Applications |
| Abstract: | In this communication, a compact design of a reconfigurable antenna array operating in the band IEEE 802.11a is presented. The proposed antenna array contains four radiating elements excited by a hybrid parallel-series-feed network. The hybrid feed technique is used to avoid the main beam squint due to frequency changes compared to series and parallel array feed topologies. Each of the four radiating elements consists of straight narrow strip inductor in parallel with an interdigital capacitor. The antenna resonant frequency is electronically controlled by placing PIN diodes switches at the resonant element's inputs. The antenna permits reconfigurable switching frequency bands between 5.25 and 5.82 GHz. The results of the return loss and pattern radiation are shown. The size of the whole antenna structure is about 64 × 18 mm2 and can potentially be used in wireless systems. |
| Author(s): | Y. M. Qasaymeh |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 3014 KB |
| Title: | Compact High Gain Multiband Antenna Based on Split Ring Resonator and Inverted F Slots for 5G Industry Applications |
| Abstract: | This paper presents the design, optimization, fabrication, and measurement of the compact high gain microstrip antenna with a split ring resonator and set of inverted-F slots along with a matching stub for sub-6 GHz5G applications. In this investigation, different iterations are visualized by incorporating inverted F slots, a split ring resonator, and a matching stub in the transmission line. The advantages of each incorporated structure are analyzed, and a hybrid antenna consisting of the combination is proposed as a final antenna configuration with the optimum results. The proposed final design attains compactness and multi-band operation. Impedance matching is improved by using the stub matched technique at the feed line. The designed antenna shows the resonances at precisely 2.1 GHz, 3.3 GHz, and 4.1GHz. The proposed antenna is suitable for mobile cellular communication such as the LTE band (2.1 GHz), n78 band (3.3 GHz), and n77 band (4.1 GHz) of 5G bands. The gain retrieved from each band attains more than 5 dB value. |
| Author(s): | R. Mishra, R. Dandotiya, A. Kapoor, P. Kumar |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2344 KB |
| Title: | Design of Cylindrical Conformal Array Antenna based on Microstrip Patch Unit |
| Abstract: | Based on microstrip patch antenna, a cylindrical conformal 8×8 array antenna is designed, which uses a T-shaped power divider to realize 64 feed channels. The simulation results show that the peak gain of planar array antenna can reach 24.8dB, while the peak gain of cylindrical conformal antenna decreases by 1.2dB and 1.7dB in phi=0° and phi=90° respectively. And the main beam direction deflects by 0° and 4° respectively. The measurement results show that the performance of the processed object is close to the simulation. After conformal with cylinder, the peak gain is 23.5dB, and the beam deflection is 4°, which verifies the feasibility of the designed cylindrical conformal array antenna. |
| Author(s): | T. Bai, D. Jiang, S. Luo, K. Zhu |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2211 KB |
| Title: | Sub-6 GHz Quad-Band Reconfigurable Antenna for 5G Cognitive Radio Applications |
| Abstract: | This article describes a quad-band frequency tunable antenna for 5G applications that operates in the sub-6 GHz frequency range. On the top side, a stubloaded square patch is printed on an inexpensive glass epoxy substrate, and on the opposite side, a C-shaped slot embedded into the partial ground plane. To achieve frequency reconfigurability with a consistent radiation pattern, the C-shaped slot and matching stub are used. The antenna is electronically frequency tunable by placing two positive intrinsic negative diodes (PIN) in the C-shaped slot and one PIN diode between the stub and feed line. The frequency is tunable between one ultra-wideband (UWB) and three communication bands based on the switching conditions of the PIN diodes. The proposed configuration is small, with a substrate dimension of 25×25×1 mm3. The antenna was fabricated, tested and found measurements result back up the simulation; it can switch between UWB (3.31.0-6.03 GHz) and three communication modes (3.31-4.32, 3.78- 4.98, 4.98-5.96 GHz). The antenna has peak gains of 1.91, 1.86, 2.0 and 2.0 dB, and radiation efficiencies of 80, 78, 83 and 86%, respectively, in the four frequency bands. The developed antenna is ideally suited for multi-functional wireless systems and cognitive radio applications since it covers the frequency bands below 6 GHz and is tunable between wide and narrow bands. |
| Author(s): | S. Ellusamy, R. Balasubramanian |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2991 KB |
| Title: | Size-Reduced Equilateral Triangular Metamaterial Patch Antenna Designed for Mobile Communications |
| Abstract: | A size-reduced equilateral triangular metamaterial patch antenna (ETMPA) is proposed for the 5G mobile communications. The new ETMPA is formed from a conventional equilateral triangular patch antenna (ETPA) by additionally loading triangular-shaped mushroom metamaterials. One ETMPA is experimentally demonstrated. It is shown to resonate at 3.488GHz. The side length is only 0.483λg, which is much smaller than that for a conventional ETPA with a length of 0.66λg. Despite its compactness, the ETMPA has an acceptable bandwidth of 2.1% and antenna gain of 6.3dBi in measurement. These performances make the compact ETMPA proposing to be used in the wireless communications at 3.5GHz. |
| Author(s): | G. Dai, X. Xu, X. Deng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2135 KB |
| Title: | Analysis of a Serrated Ground Plane for a Low-Loss Reflectarray Antenna |
| Abstract: | A novel serrated ground plane (NSGP) for na low-loss reflectarray antenna is presented in this paper. Compared with a conventional smooth ground plane (CGP), the NSGP consists of a series of serrated elements, which can reflect the incident waves in the main beam direction, so the losses of the reflectarray can be effectively reduced. The principle and losses of reflectarray antennas are studied and analyzed. Then, a low-loss NSGP is proposed, and two design methods for the NSGP are given in this paper. Finally, a reflectarray antenna with elements arranged in a 15×15 grid is designed, simulated and measured with the NSGP and CGP respectively within the frequency from 12.88 to 13.88GHz. The results show that the reflectarray antenna with the NSGP can effectively utilize the reflected waves and has a maximum higher gain of 0.681 dB compared with the gain of the reflectarray with the CGP. This NSGP has a potential to be used in the high accurate design of the reflectarray which requires to realize beam forming, low-loss, high-efficiency, etc. |
| Author(s): | J. Ren, H. Wang, W. Shi, M. Ma |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2634 KB |
| Title: | SDR Based Modulation Performance of RF Signal under Different Communication Channel |
| Abstract: | Hardware components are an integral part of Hardware Define Radio (HDR) for seamless operations and optimal performance. On the other hand, Software Define Radio (SDR) is a program that does not rely on any hardware components for its performance. Both of the latter radio programmers utilize modulation functions to make their core components from signal processing viewpoint. The following paper concentrates on SDR based modulation and their performance under different modulations. The bit error rate (BER) of modulations such as PSK, QAM, and PSAM were used as indicators to test channel quality estimation in planar Rayleigh fading. Though it is not commonly used for channel fading, the method of the adder determines the regionally segmented channel fading. Thus, the estimation error of the channel change substantially reduces the performance of the signal, hence, proving to be an effective option. Moreover, this paper also elaborates that BER is calculated as a function of the sample size (signal length) with an average of 20 decibels. Consequently, the size of the results for different modulation schemes has been explored. The analytical results through derivations have been verified through computer simulation. The results focused on parameters of amplitude estimation error for 1dB reduction in the average signal-to-noise ratio, while the combined amplitude deviation estimation error results are obtained for a 3.5 dB reduction. |
| Author(s): | S. Habib |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2204 KB |
| Title: | Light Wave Propagation Model for Indoor Visible Light Communication Systems Employing Small LED Sources |
| Abstract: | The aim of the present work is to build a robust and computationally efficient model for the light wave propagation in indoor visible light communication (VLC) systems. It is assumed that a small (point) LED source is used inside a room of relatively small dimensions (room area ≤ 5m × 5m). The light wave is treated as an electromagnetic wave suffering multiple reflections on the walls of the room. The Geometrical Theory of Diffraction (GTD) is applied for evaluation of the light wave reflection on the rough walls of the room. Also, the present work is concerned with developing a new computational method for the assessment of intersymbol interference (ISI) encountered in such indoor VLC systems. The signal strength, the power of ISI, and hence, the signal-to-ISI ratio (SISIR) are evaluated over the horizontal plane of the mobile units (at a height of about 1m above the room floor). The effects of the room dimensions and some structural parameters such as the reflectance of the side walls on the SISIR are numerically investigated. |
| Author(s): | M. M. A. Elsaaty, A. Zaghloul, K. F. A. Hussein |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2441 KB |
| Title: | Signal Propagation Modeling Based on Weighting Coefficients Method in Underground Tunnels |
| Abstract: | The propagation of electromagnetic waves guided in tunnels and mines is an area of scientific study which is hard to model due to multiple reflections on walls and surrounding obstacles. A novel propagation model for underground tunnels based on the weighting sum of the log-distance propagation model, the modified waveguide model and, the far zone propagation model for the ultra-high frequency (UHF) band is proposed in this paper. The propagation model is divided into five regions based on the distance between the transmitter and the receiver. Each region shows a different propagation characteristic and modeled with weighting sum of the base propagation models. Our model was tested in a tunnel with 2 m x 1.5 m cross-section and 250 m length. Measurement results are consistent with the proposed propagation model. |
| Author(s): | Y. Karaca, O. Tamer |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2308 KB |
| Title: | Characteristic Analysis and Control of a Rotary Electromagnetic Eddy Current Brake |
| Abstract: | This article designs an electromagnetic rotating eddy current brake (ECB), which has the advantages of no wear and low noise compared with traditional friction brake. First, using the magnetic circuit analysis model, a theoretical calculation formula of the ECB’s braking characteristics is given. The results show that the braking torque is negatively correlated with the thickness of the air gap as well as the electrical conductivity and the relative magnetic permeability of the brake disc material, and positively correlated with the number of ampere turns and the number of electromagnet poles. Secondly, a three-dimensional finite element (FE) model of the brake is established. The results of braking torque-speed characteristics between finite element calculation and theoretical analysis are compared, and the reasons for the differences between the two are explained. Using the FE model, the influence of the design parameters on torque characteristics is studied. Combined with the theoretical analysis model, the results are explained accordingly, providing a reference for the optimal design of the brake. Finally, a controller for the electromagnetic rotating eddy current brake is designed to control the amplitude of the desired braking torque. |
| Author(s): | Q. Ren, J. Zhang, H. Zhou, J. Luo |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2667 KB |
| Title: | Modelling of Electromagnetic Fields for Shielding Purposes Applied in Instrumentation Systems |
| Abstract: | In any sensory system, the Electromagnetic (EM) shielding of the channel-carrying signal is a fundamental technique to provide a noise-immune measurement system. Severe failures and uncertainty may occur if the external EM fields interfered with the measurements. Typically, the shielding is realized by enclosing the channel-carrying signal with thinconductive hollow structures. However, with such structures, it is required to provide access to the interior components from the outside, for wires' connections, or better heat dissipation. This can be considered as a weakness in such the external magnetic fields can penetrate through the shielding structure. In this paper, the EM shielding effectiveness is considered for long hollow-cylinder structures with slots. The induced eddy current in thin-conductive shielding systems with slots together with the magnetic fields at different conditions are modeled. The objective is to determine the impact of the integrated slots along with the structure. The influence of the slots' sizes (α) and position relative to the excitation magnetic field (i.e., the declination angle (β)) are investigated to evaluate the shielding effectiveness by means of the determination of the shielding factor. The results reveal the inherent relationship between the shield parameters and shielding effectiveness. The shielding effectiveness deteriorates by the slots' integration within the shielding surface. However, decreasing the size of the slots improves the shielding, significantly, towards the shielding effectiveness of the continuous cylindrical structure. Additionally, utilizing the symmetry in the structure positioning the slots in the direction perpendicular to the magnetic field flux improves the shielding effectiveness, drastically. Such a model can be considered to evaluate the degree of effectiveness or success of integrating opening slots within the shielding structure, which can be applied to different types of instrumentation systems specifically at the sensor-electronics interface. |
| Author(s): | A. M. Dagamseh, Q. M. Al-Zoubi, Q. M. Qananwah, H. M. Jaradat |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2230 KB |
| Title: | Electromagnetic Acoustic Transducer for Detection and Characterization of Hidden Cracks inside Stainless Steel Material |
| Abstract: | Industrial structure are exposed to microstructural changes caused by fatigue cracking, corrosion and thermal aging. Generally, a hidden crack is very dangerous because it is difficult to detect by Non- Destructive Evaluation (NDE) techniques. This paper presents a new approach to estimate the hidden cracks dimensions inside a stainless steel plate based on the EMAT signal. The received signal by EMAT is simulated using the Finite Element Method (FEM). Then, the identification of the hidden crack sizes is performed via the combination of two techniques; the first one is the Time-of-Flight (ToF) technique which was applied to estimate the crack height by the evaluation of the difference between the ToF of the healthy form and the defective form. Then, the crack width is estimated by the solution of the inverse problem from the received signal based on a meta-heuristic algorithm called Teaching learning Based optimization (TLBO). The obtained results illustrate the sensitivity of the EMAT sensor to the variation of the crack sizes. Moreover, the quantitative evaluation of the cracks dimensions, show clearly the efficiency and reliability of the adopted approache. |
| Author(s): | H. Boughedda, T. Hacib, Y. L. Bihan, M. Chelabi, H. Acikgoz |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2602 KB |
| Title: | Reduction of Cogging Torque in AFPM Machine Using Elliptical-Trapezoidal-Shaped Permanent Magnet |
| Abstract: | The reduction in cogging torque enables smooth operation and an increase in the torque density of the machine. This research aims to minimize cogging torque in dual rotor single stator axial flux permanent magnet (AFPM) machine. Reduction in cogging torque makes the back EMF sinusoidal and reduces the torque ripples in AFPM machine. In this paper, an elliptical trapezoidal-shaped permanent magnet (PM) is proposed to minimize torque ripples of the AFPM machine. The 3D finite element analysis (FEA) is used for the analysis of AFPM machine. The optimization of AFPM machine is done by employing the asymmetric magnet-overhang along with the parameters of elliptical-shaped PM using Genetic algorithm (GA). |
| Author(s): | S. Ali, J. Ikram, C. P. Devereux, S. S. H. Bukhari, S. A. Khan, N. Khan, J.-S. Ro |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2990 KB |
| Title: | Characteristics Analysis of Double-Sided Permanent Magnet Linear Synchronous Motor with Three-Phase Toroidal Windings |
| Abstract: | This paper proposes three-phase 120° phase belt toroidal windings (120°-TW) and are applied in a double-sided permanent magnet linear synchronous motor (DSPMLSM), in which the incoming ends of all coils are on the same side and have the same incoming direction. First, the structure of the proposed motor is introduced and its operation principle is analyzed by describing the variation in the armature magnet field versus time. Second, based on the similar volume, magnetic load and electrical load, the initial parameters of the DSPMLSM with different winding arrangements are presented. Then, the finite-element models (FEMs) of the DSPMLSM with 120°-TW (120°-TWDSPMLSM) and traditional toroidal windings (TTW) are established to analyze the distribution of magnetic field, back electromotive force (back-EMF), detent force, thrust, efficiency and so on. Besides, the primary optimization of the detent force is designed. Finally, the results show that the thrust density and efficiency of the 120°-TWDSPMLSM is higher than that of DSPMLSM with TTW (TTWDSPMLSM). |
| Author(s): | X. Chai, J. Si, Y. Hu, Y. Li, D. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2233 KB |
| Title: | Electronically Reconfigurable WLAN Band-Notched MIMO Antenna for Ultra-wideband Applications |
| Abstract: | A low-profile electronically reconfigurable WLAN band-notched dual port multiple-input multipleoutput (MIMO) antenna design for ultra-wideband applications has been presented. Antenna elements exhibit good impedance match (S11 ≤ -10 dB) over entire ultrawideband (3.1 to 10.6 GHz) spectrum. The decoupling structure is used to improve isolation (S12/S21) above 20 dB over entire UWB band. Moreover, reconfigurable band-notching is achieved by inserting PIN diodes along the inverted L-shaped slots, in each radiator. Notch at WLAN (5.5 GHz) frequency band is achieved by switching the PIN diode to ‘OFF’ state. The antenna design is fabricated as well as measured, and the results suggests that the proposed design with switchable WLAN band-notch characteristics is suitable candidate for ultra-wideband applications. |
| Author(s): | A. Quddus, R. Saleem, S. Arain, S. R. Hassan, M. F. Shafique |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2079 KB |
| Title: | Circuit Modelling Methodology for Dual-band Planar Antennas |
| Abstract: | This paper presents a simple and systematic approach to determine the equivalent frequencyindependent circuit model for a dual-band planar antenna. The Foster Canonical network synthesis technique with two RLC tanks has been employed to generate the two resonant bands of the antenna. The transfer function model is subsequently refined using a data fitting algorithm (viz the Nelder-Mead simplex algorithm). Parametric adjustments are performed at the final stage in order to further improve the accuracy of the final parameters. |
| Author(s): | K. H. Yeap, T. Meister, Z. X. Oh, H. Nisar |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2097 KB |
| Title: | Novel Methodology to Assess RF Performance of Co-located MIMO Radar Systems Transmitting Binary Phased Coded Waveforms |
| Abstract: | In this work an experimental radar testbed and dual directional couplers (DDC) are used to collect measurements of the forward and reverse waves at each element, its mutual coupling, and beam-patterns. The collected measured data is used to validate a methodology for assessing radio frequency (RF) performance of a co-located multiple-input multipleoutput (MIMO) radar system transmitting binary phased coded (BP) waveforms. The estimated and measured active reflection coefficient (ARC) and beam-patterns are presented. The effect of different excitations and mutual coupling on the radiated fields is also presented. |
| Author(s): | N. Colon-Diaz, D. Janning, P. M. McCormick, J. T. Aberle, D. W. Bliss |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2124 KB |
| Title: | Model Order Reduction of Cardiac Monodomain Model using Deep Autoencoder Based Neural Networks |
| Abstract: | The numerical study of electrocardiology involves prohibitive computational costs because of its complex and nonlinear dynamics. In this paper, a lowdimensional model of the cardiac monodomain formulation has been developed by using the deep learning method. The restricted Boltzmann machine and deep autoencoder machine learning techniques have been used to approximate the cardiac tissue’s full order dynamics. The proposed reduced order modeling begins with the development of the low-dimensional representations of the original system by implementing the neural networks from the numerical simulations of the full order monodomain system. Consequently, the reduced order representations have been utilized to construct the lower-dimensional model, and finally, it has been reconstructed back to the original system. Numerical results show that, the proposed deep learning MOR framework gained computational efficiency by a factor of 85 with acceptable accuracy. This paper compares the accuracy of the deep learning based model order reduction method with the two different techniques of model reduction: proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD). The model order reduction deploying the deep learning method outperforms the POD and DMD concerning the modeling accuracy. |
| Author(s): | R. Khan, K. T. Ng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 8 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1999 KB |