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Title: ACES Journal September 2019 Cover
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: ACES Journal September 2019 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: ACES Journal September 2019 Full
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Pattern Synthesis for Array Antennas based on Interpolation Gravitational Search Algorithm
Abstract: A new algorithm known as interpolation gravitational search algorithm (IGSA) is proposed in this paper when be used to synthesize pattern for array with complicated side lobe and notch. First, a novel and adjustable coefficient q for inertia mass is introduced, which can render the particle large in inertia mass get larger and more attractive to other particles to access to more optimal location, so the convergence can be accelerated through varying the discrepancy of inertia mass Mi(t) of particles in a specific population. Second, a simplified quadratic approximation algorithm (SQA) is interpolated that can make the algorithm perform better in the aspect of optimum seeking, so the computational accuracy can be increased through utilizing the stronger local search ability of SQA. To verify the validation of the algorithm, the proposed IGSA is applied to commit pattern synthesis in terms of different targets. Simulation results show that the IGSA, as a whole, is better than the other algorithms the same kind, mainly because the IGSA can be possessed of faster speed in convergence and perform more accurate in optimization.
Author(s): C. Sun, J. Ding, C. Guo, J. Liu
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: CPW-fed UWB Antenna with Tri-band Frequency Notch Functionality
Abstract: In this paper, a UWB antenna exhibiting frequency suppression characteristics for WiMAX and WLAN spectra is modeled and analyzed. The proposed geometry is composed of a circular radiating element. Impedance matching at higher frequencies is achieved by incorporating steps near the feedline. Introduction of arc-shaped slots in the radiator results in significant band rejection for 3.3-3.7 GHz, 5.15-5.25 GHz and 5.725-5.825 GHz. Designed antenna has an impedance bandwidth (VSWR < 2) of 9 GHz ranging 3-12 GHz. A prototype of the proposed model is fabricated on a low loss substrate. Comparative study of measured results to the simulated results depicts that the performance parameters of the antenna, e.g., impedance bandwidth, S-parameters and radiation characteristics meet the criteria for wideband applications.
Author(s): S. I. Jafri, R. Saleem, K. Khokhar
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Ultra-wideband Planar Log-periodic Slot Antenna with Exponential Shapes on Slot Edges
Abstract: An improved method of using exponential curve shape on edges of log-periodic slots to decrease resonances and further reduce the antenna size is proposed. The proposed method is adopted to design a planar log-periodic slot antenna for ultra-wideband (UWB) applications. Numerical investigation shows that resonant frequencies can be decreased around 12.3% in low frequencies compared with the conventional planar log-periodic slot antenna with regular shape on edges of slots. Measured and simulated reflection coefficients and radiation patterns of the proposed antenna agree well with each other to demonstrate the validity. The measured |S11| shows that the operating frequency range (|S11| below -10 dB) is from 2.9 GHz to 11.36 GHz, covering the UWB spectrum (3.1 – 10.6 GHz). The proposed antenna has good radiation characteristics and antenna gains. The proposed antenna is a good candidate for the UWB applications.
Author(s): W.-C. Weng, M.-C. Chang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Design of a Frequency Reconfigurable Notched-Band Ultra-Wideband Antenna for Cognitive Radio Applications
Abstract: This paper proposes a frequency reconfigurable notched-band UWB antenna design, which is capable of wide band rejection. We begin with a conventional reconfigurable modified-square monopole printed antenna and insert a U-shaped slot to create the rejection band. Next, we add two identical SMV1249 varactor diodes with variable capacitances in the created slots to tune the rejected band. We modify the capacitances, which, in turn, controls rejected band by controlling the reverse bias voltage applied across the varactor diodes. The proposed structure has been simulated, optimized, fabricated and experimentally tested. Good agreement has been achieved between the simulation and measurement results. Experimental results show that when the bias voltage is varied from 0 to 7 V, the antenna can be reconfigured to achieve various rejection frequency bands, and to maintain good impedance match as well as stable radiation patterns over the explored frequency band ranging from 1 to 6 GHz.
Author(s): M. Alsulami, H. Rmili, S. Mehri, B. Hakim, M. Sheikh, R. Mittra
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: UWB MIMO Antenna for High Speed Wireless Applications
Abstract: The paper proposes a MIMO antenna composed of two elements in the form of UWB monopole antennas. Polarization diversity of the proposed antenna is obtained locating the two elements perpendicularly on a common substrate. Also the isolation between elements is accomplished without using any extra decoupling structures. The two monopoles antennas with half elliptical shape are fed with asymmetric coplanar strip (ACS). The presented antenna is located on substrate 48 × 28 mm2 in total size. The distance between the two elements is 15 mm that is 0.15λ0 at 3GHz. The antenna was designed to work effectively from 3 to 11.5 GHz with reflection coefficient better than -10 dB and isolation lower than 18 dB. In addition, antenna with elements located in parallel was designed to show the advantage of the original design. Envelope correlation coefficient, diversity gain and channel capacity loss document the antennas behavior. The antenna was fabricated and measured. Measurement validated the simulation and showed that the designed antenna can be well applied in UWB MIMO systems.
Author(s): A. A. Ibrahim, J. Machac, R. M. Shubair
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Compact Design of Non-uniform Meta-surface for Patch Antenna Main Beam Steering
Abstract: A compact design of non-uniform metasurface for patch antenna main beam steering is presented in this paper. The proposed design is realized using printed circuit board technology. By adding the non-uniform meta-surface to a patch antenna, the mainbeam direction of the patch antenna can be steered by an angle up to 30° from the boresight direction. The metasurface together with the patch antenna here is called meta-surfaced antenna, which has a very compact structure since there is no air gap between the metasurface and the patch antenna. The meta-surfaced antenna is studied and designed to operate around 2.45GHz. To verify the results of simulation, the metasurfaced antenna is fabricated and measured. Measured results show that the antenna has an operating bandwidth from 2.35-2.5GHz and peak realized gain of 7.1dBi.
Author(s): H. Zhu, Y. Qiu, J. Bai, G. Wei
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Design of the Tri-band UWB Microstrip Patch Antenna for WBAN Applications
Abstract: The increasing commercialization of the Wireless Body Area Networks (WBAN) in various healthcare facilities poises for the growing network resources competition in the Physical layer. In remote health monitoring, energy scarcity and limited bandwidth compromise demand for optimized network lifetime and high data rate of the multimedia information with reduced spectral noises. In this paper, we have designed a compact Tri-band antenna with three rejection bands for WBAN applications. The rectangular antenna patch is etched on RT/Duroid substrate. The patch consists of flat chamfers, semi-circular, and elliptical slots. The simulated antenna resonates at three distinct frequencies; 6.39 GHz, 7.15 GHz, and 9.89 GHz each operating at the ultrawideband (UWB) with a return loss (|S11|) > 10 dBm. The antenna is designed using Computer Simulation Technology software (CST-2016) and analyzed for its return loss, field radiation, bandwidth (cumulative BW, 3473.8 MHz), and voltage standing wave ratio (VSWR<1.5). Simulation results show antenna performance characteristics which suit various WBAN applications.
Author(s): K. G. Mkongwa, Q. Liu, C. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: RF MEMS Switches Enabled H-Shaped Beam Reconfigurable Antenna
Abstract: This work presents a novel RF MEMS-based pattern reconfigurable antenna capable of steering beam in three different directions. The proposed H-shaped microstrip antenna is based on the basic structure of a dipole antenna and forms an ‘H’ shape by combining two dipoles in reverse fashion. The proposed antenna provides pattern reconfigurability at a single resonant frequency of 1.8 GHz, that lies in L-band. The optimized simple structure of the proposed antenna allows easy incorporation of single pole single throw (SPSTRSMW101) RF MEMS switches. The antenna is simulated using electromagnetic (EM) simulators (HFSS and IE3D). The proposed antenna is fabricated on RT Duroid substrate with 2.2 dielectric constant, and 1.75 mm thickness. The ON and OFF state of RF MEMS switches enables three different scenarios of operation with peak gains of 6.25 dBi, 6.28 dBi, and 4.01 dBi respectively. For validation of pattern reconfigurability the antenna is tested using time domain antenna measurement system and found to have a good agreement with the simulated results.
Author(s): W. M. Abdulkawi, A.-F. A. Sheta, W. A. Malik, S. U. Rehman, M. S. Alkanhal
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: A Reconfigurable Crossed Dipole Antenna for Polarization Diversity Using Characteristic Mode Theory
Abstract: A novel printed crossed dipole antenna with reconfigurable circular and linear polarization is proposed. This antenna consists of a pair of L-shape elements and a narrow gap on each arm for inserting a conductive metal tab as an ideal switch in the center of the gap to control its on-off status. The theory of characteristic modes has been used to design and analyze the proposed antenna. Based on the presented idea, a prototype of such antenna has been constructed with the center operating frequency at about 2500 MHz. The experimental results have been presented and compared with those obtained from the simulation showing a good agreement. The antenna is low cost and possesses simultaneous circular and linear polarization which has not been reported in the literature for single-feed crossed dipole antennas.
Author(s): A. Nikfal, G. Dadashzadeh, M. Naser-Moghadasi
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Broadband Microwave Absorber based on End-loading Folded-Dipole Array
Abstract: Microwave absorbers have been widely used in electromagnetic compatibility, radar absorbing material and cloaking etc., and therefore attract much attention in recent years. In this work, a microwave absorber based on an array of receiving folded-dipoles with a grounded air spacer is proposed. The cell of the absorber can be seen as a three resonators in tandem formed by dipole-mode and stub-modes of the receiving folded dipole and the grounded spacer with thickness of λ/4, i.e., an equivalent three-pole filter. Based on the equivalent circuit, the impedance matching during a wide frequency range can be achieved. Moreover, to verify the proposed technique, a prototype of dualpolarized absorber is fabricated and measured. A little variation between the simulation and measurement results are observed, however, the relative bandwidth can still reach up to 105%. In addition, compared with other absorbers constructed with metal and lumped elements, the proposed absorber has a high ratio of bandwidth/thickness, which is around 8.5 and be with dual-polarizations.
Author(s): Y. Chang, Y. L. Chow
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Three-bit Unit-cell with Low Profile for X-Band Linearly Polarized Transmitarrays
Abstract: In this paper, we present a three-bit phase resolution and low profile unit-cell structure for X-band passive transmitarrays. The unit-cell is implemented using four metallic layers printed on two substrates separated by an air gap. The phase shift is achieved by a combination between current flow modification on middle layers and the variation of the size of path elements. Eight unit-cells are optimized to provide eight phase states with a step of 45°. Experimental results are conducted by using WR-90 waveguide to validate the design. These eight unit-cells cover a wide -3 dB transmission bandwidth of 15% and exhibit a low thickness of 0.18λ0.
Author(s): B. D. Nguyen, M. T. Nguyen
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Circularly Polarized Circular Slit Planar Antenna for Vehicular Satellite Applications
Abstract: A compact, ultra light weight and efficient asymmetric circular slit circularly polarized patch antenna is proposed for vehicular satellite communications. The circular slit in the corners of the patch is utilized for achieving circular polarization and an edge-fed through a microstrip feed line incorporates a quarter-wave transformer for impedance matching. Simulation results indicate an improvement in cross polarization isolation. The proposed antenna is fabricated using RT/DUROID 5880 material which is lighter, flexible and less expensive compared to the commercially existing ceramic corner curtailed patch antennas. The measured results indicate a reflection coefficient of -24.1 dB at resonant frequency, impedance bandwidth of 490 MHz ranging from 11.03 GHz to 11.52 GHz, axial ratio bandwidth of 180 MHz ranging from 11.16 GHz to 11.34 GHz and constant gain through the operating bandwidth with an apprehended peak gain of 5.6 dB. Experimentations affirmed that measured radiation results of the suggested antenna are similar to the simulation results and can be utilized as vehicle roof mounted antennas for diverse satellite communication applications.
Author(s): E. Abishek B., A. Raaza, S. Ramesh, S. Jerritta, V. Rajendran
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: High Impedance Surface Application to Dipole Antenna Design
Abstract: In this paper, HIS (High Impedance Surface) are used, in order to verify their utilities; we have considered two different structures as a ground. The first is mushroom EBG (Electromagnetic Band Gap) structure which is composed of several patches with a ground connecting via, where the second is 2D metamaterial structure with resonant rings. Both the structures are investigated by simulation and compared at the frequency 12 GHz. The metamaterials proprieties are successfully verified around the resonant frequency.
Author(s): S. Berkani, Y. Lamhene, M. Hadj-Sadok, H. Baudrand
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: On the Design of a Novel Fractal Antenna for Spectrum Sensing in Cognitive Radio
Abstract: The present paper reports on the development of a novel compact fractal microstrip patch antenna for spectrum sensing in cognitive radio. The geometrical design of the proposed fractal antenna is optimized using nature inspired Moth Flame Optimization (MFO) method. The optimized antenna is having broadband characteristic within two bands (6.206 - 7.864 GHz, 23.56%) and (14.95 - 20 GHz, 28.89%), which are specified for IEEE C-band, Ku-band and K-band applications respectively. The proposed fractal antenna is also having high peak gain of 7.26 dBi at 18.04 GHz and omnidirectional radiation pattern at all frequencies. The performance of the proposed antenna is also validated experimentally by having a comparison of simulated results with the measured results. The proposed design offers 45.54% reduction in antenna physical size (copper required) as compare to a rectangular patch antenna of same size.
Author(s): M. Aggarwal, A. P. S. Pharwaha
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Compact and Coding Expandable Chipless RFID Tag with Bending Arms
Abstract: In order to construct a compact chipless RFID tag with scalable coding capacity, a design is proposed that includes bending arms along both sides of the microstrip transmission line. Each bending arm produces a resonant frequency, which indicates one bit. And the bending structure can effectively reduce the coupling between units. A 12-bit chipless RFID tag with dimensions of 37×17.7mm2 is designed with a frequency band from 5GHz to 6.05GHz. And a 40-bit chipless RFID tag is proposed with a frequency band from 2.95GHz to 5.65GHz. Both amplitude and Group Delay responses of the proposed tag are measured and analyzed. The measurement results are in good agreement with the simulation results. The measured results achieve stability and high capacity the coded information.
Author(s): H. Zhu, X. Li, S. Jia
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Miniaturized Elliptical Slot Based Chipless RFID Tag for Moisture Sensing
Abstract: This paper presents a compact 10-bit chipless radio frequency identification (RFID) sensor tag. The proposed structure has overall size of 22.8 mm×16 mm and possesses the capability of identification of data as well as moisture sensing of the tagged objects. The resonating structure comprises of elliptically shaped slots in a nested loop manner, investigated for three substrates that are Rogers RT/duroid®/5880, Taconic (TLX-0) and Rogers RT/duroid ®/5870. The prototype is fabricated by using Rogers RT/duroid®/5880, and moisture sensing is realized by deploying heat-resistant sheet of Kapton®HN (DuPontTM) on the smallest slot considered as sensing slot over the aspired frequency spectrum of 3.5 GHz-15.5 GHz. The proposed tag is quite suitable for cost effective applications and can be deployed on the conformal surfaces for identification and sensing purposes.
Author(s): I. Jabeen, A. Ejaz, M. A. Riaz, M. J. Khan, A. Akram, Y. Amin, H. Tenhunen
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Design of High Order Cross-Coupled Constant Absolute Bandwidth Frequency-Agile Bandpass Filters
Abstract: Novel high order constant absolute bandwidth (ABW) cross-coupled electrical tunable bandpass filters (BPFs) are proposed. Microstrip cross-coupled tunable resonators are designed and investigated to meet the coupling requirement of the tunable BPF with constant ABW. A thorough theoretical analysis is derived to determine the performance of the proposed filter and verify the initial values of design parameters. To verify the design concept, two prototypes are fabricated and measured. The measurements show that the proposed four-order filter has a -3 dB ABW of 119.5±2.5 MHz with 1.31~1.98 GHz tuning frequency. And the proposed six-order filter has a -3 dB ABW of 102±6 MHz with 1.39~2.07 GHz tuning frequency. High selectivity has been achieved in the proposed filter by TZs (transmission zeros) beside the passband, good agreement between simulated and measured results has been demonstrated.
Author(s): D. Tian, Q. Feng, Q. Xiang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Miniaturized High Split Ratio Bailey Power Divider Based on Multi-Ring Split Ring Resonators
Abstract: In this paper, a miniaturized microstrip-based Bailey power divider is proposed by incorporating split ring resonators. New analytical design equations are derived for predefined power split ratios. To validate the proposed design methodology, two miniaturized dividers with 5:1 and 20:1 split ratios at 600 MHz are simulated, fabricated and measured. Simulated and measured results agree very well and show input port matching better than -15 dB and -20 dB at the design frequency, for the 5:1 and 20:1 dividers, respectively. The desired high split ratios are achieved with transmission parameters, S21 and S31, of -1.9 ± 0.1 dB and -8.9 ± 0.5 dB for the 5:1 divider, and -0.9 ± 0.1 dB and -13.9 ± 1.5 dB for the 20:1 divider, respectively. Furthermore, a size reduction better than 65% is achieved as compared to conventional footprints.
Author(s): O. J. Jibreel, N. I. Dib, K. A. Shamaileh
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: A General Mutual Inductance Formula for Parallel Non-coaxial Circular Coils
Abstract: In this paper, we present a complete derivation of a new formula for calculating the mutual inductance between two parallel non-coaxial circular coils by using the magnetic vector potential. Although this problem has been studied by Kim et al, their formula is wrong when the two parallel circulars are non-coaxial. The newly derived formula can not only clarifies the origin of the error introduced in Kim’s work, but also can be reduced to the well-known F. W. Grover formula. Different from the Grove’s formula that has various cases of the singularities, the new formula enables to simplify all the singular cases into single situation. The singularity in our formula has the clearly geometrical significance, i.e., the point located in one projected circular coil overlapped with the center of another one, which can be easily tackled by the principal value integrals. In order to check the validity of our formula, we have investigated the mutual inductance of the circular coil of the rectangular cross section, and the results demonstrate the correctness of our formula as compared with the other approaches, such as the Neumann’s formula, Grover’s formula and other published data. In addition, our formula is capable of handling the topics involving the circular coils such as the coils of the rectangular cross section, wall solenoids, disk coils and circular filamentary coils etc. In conclusion, our newly derived formula is of great importance for the electromagnetic applications concerning the calculation of the mutual inductance of the two parallel non-coaxial circular coils.
Author(s): K.-H. Song, J. Feng, R. Zhao, X.-L. Wu
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: HMSIW Cavity Filters Employing Various Complementary Split-Ring Resonators for Microwave Remote Sensing Applications
Abstract: In this work, bandpass filters employing half-mode substrate integrated waveguide (HMSIW) cavities and various modified complementary split-ring resonators (CSRRs) are presented. The two modified CSRRs, which are called as Type-I and Type-II CSRRs, can exhibit larger effective inductance and capacitance, and eventually to contribute to the size miniaturization of the resonators. Thereafter, as the two CSRRs are independently loaded into HMSIW cavities, the newlyformed HMSIW-CSRR cavity resonators can achieve more size reduction as compared with the HMSIW cavity with the conventional CSRR. To demonstrate the proposed concept, two HMSIW cavity bandpass filters independently loaded with the proposed Type-I and Type-II CSRRs are implemented. Experimental results shows that measurements of the proposed filters agree with their corresponding simulations well. Meanwhile, as compared with some similar works, the two proposed filters achieve size reduction of 76.8% and 78.6%, respectively, as well as good selectivity, illustrating their suitability for the system integration application in microwave remote sensing and radar systems.
Author(s): L. Wang, Z. He, Y. M. Huang, S. Ding, M. Bozzi
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Super Wide Band Tunable Microstrip BPF Using Stub Loaded MMR
Abstract: A simpler structure of super wide band (SWB) tunable microstrip band pass filter (BPF) using stub loaded multimode resonator (MMR) is presented here. The MMR is formed by loading a single openended shunt stub at the center with a simple stepped impedance resonator. By incorporating this MMR with two interdigital parallel coupled feed lines, a novel SWB tunable BPF is formed. The BPF is fabricated using FR-4 substrate of 1.6 mm thickness with dielectric constant of 4.4 and simulated using high frequency structure simulator (HFSS) software. The simulated and measured results are in good agreement with each other, with a wide fractional bandwidth (FBW) of 179%. The measured insertion loss is less than -0.9 dB throughout the pass band of 3.1 GHz-15.4 GHz with the return loss higher than 11.5 dB. The group delay of the filter is relatively constant and less than 0.3 ns over the desired pass band.
Author(s): A. Sengupta, S. R. Choudhury, S. Das
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: A Compact Rejection Filter based on Spoof Surface Plasmon Polartions and Folded Split-Ring Resonators with Controllable Rejection Bandwidth
Abstract: A novel rejection filter composed of the single comb-shaped spoof surface plasmon polariton (SSPP) and the folded split-ring resonators (FSRR) is proposed in this letter. By embedding the FSRRs into grooves of the low-pass SSPP filter, the compact rejection filter with the same size as the low-pass filter is consequently realized. Compared with traditional ones, the proposed filter provides simpler structure, more compact size, lower insertion loss, higher frequency and controllable rejection bandwidth. The dispersion interprets the transmission modes of the rejection SSPP unit. And the approaches of controlling the rejection band prove the fine controllability in the filter. The fabricated filter has a size of 3.23λg×0.24λg, a central rejection frequency of 18.43 GHz, a fractional rejection bandwidth of 7.8%, maximum rejection depth of 42 dB, and an average passband insertion loss of 2.5 dB. The simulated rejection bandwidth controllable range is 4.0%~6.8%. Improved performances confirm the advantages of the proposed filter.
Author(s): L. Li, P. Chen, P. Zhu, K. Yang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Non Destructive Testing of Cylindrical Ropes through the Parametric Transformer
Abstract: In order to ensure the safe operation of wire ropes, non-destructive testing methods are being applied to inspect wire ropes. Any geometrical discontinuity in magnetic permeability in the magnetized wire rope will impact the magnetic field conveyed by the rope, under a proper excitation. In this work, the electromagnetic device known as “parametric transformer” has is proposed for the non-destructive testing of ferromagnetic bodies having cylindrical symmetry, as tubes and ropes. The principle of its functioning is described by means of an equivalent magnetic network and a more rigorous approach using the Partial Element Equivalent Circuit (PEEC) method. Then, the proposed principle has been tested experimentally through the realization of a model which has confirmed the expected results.
Author(s): D. Romano, T. Scozzafava, G. Antonini
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Multilayer Half-Mode Substrate Integrated Waveguide Wideband Coupler with High Selectivity
Abstract: A novel 3dB wideband coupler with enhanced selectivity has been proposed and developed in multilayer HMSIW topology. Periodic ginkgo leaf slots (GLS) are etched on top layer of HMSIW to realize a pass-band combining with high-pass characteristics of HMSIW. The novel GLS cells have stop-band characteristics aiming to improve the frequency selectivity and extend the upper stop-band. Moreover, the roll-off at the upper side is very sharper. A continuous coupling slot is etched in the conductor layer at the broadwall of HMSIW. Coupling takes place through the long, offset slot, which features a flexible design providing a wide coupling dynamic range with wideband characteristics. Detailed design process is introduced to synthesize a wideband filtering HMSIW coupler with better stopband rejection. The novel coupler is showing a 34.9% coupling bandwidth at 8.87 GHz with good isolation, reflection and out-of-band rejection performances. Its stop band is from 13.8 to 17.6GHz with the rejection more than 40dB. Good agreement is obtained between the simulated and measured results of the proposed structure.
Author(s): Z. Zhang, Y. Fan, Y. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Design and Finite Element Analysis of a Novel Reverse Salient Pole Permanent Magnet Synchronous Motor
Abstract: Since traditional permanent magnet synchronous motor (PMSM) with salient pole effect has a lower d- than q-axis inductance, the maximum torque has a power angle higher than 90 degrees, which poses threat to demagnetization when the motor runs under load. To solve the problem, a novel PMSM with reverse salient pole is designed and optimized to realize the characteristic of Ld > Lq in this paper. Firstly, the electromagnetic design of reverse salient pole PMSM is carried out, followed by finite element analysis (FEA) of traditional PMSM and reverse salient pole PMSM. The simulation results show that air-gap flux density and noload back EMF of reverse salient pole PMSM is closer to sinusoidal wave compared with the traditional PMSM. The danger of permanent magnet demagnetization is reduced due to Ld > Lq . In addition, reverse salient pole PMSM improves the maximum torque and overload capacity and has less loss and higher efficiency in steady-state operation. Finally, the optimal design of reverse salient pole PMSM is carried out. From the comparison of the simulation results, the optimized structure is superior to reverse salient pole PMSM in these performances, which shows that the design is reasonable.
Author(s): X. Deng, S. Gong, R. Li, J. Zhou
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Trajectory Tracking of Rotating Shaft with Active Magnetic Bearings under Different Reference Signals
Abstract: Using magnetic levitation technology to implement a reference signal can avoid fluid mechanical surge and better control the movement of motorized spindle-mounted cutting tools. Magnetic levitation has the advantages of no friction, no mechanical wear, and high efficiency. In this paper, the performance of axial trajectory tracking control of active magnetic bearings with a classical proportional-integral-derivative (PID) controller is studied. First, the principles of trajectory tracking with an active magnetic bearing system are expounded, and the mechatronics models of such a system are established. Then, a PID controller is designed and trajectory tracking performance using different reference signals is verified by simulation and experiment. The results show that PID-based control of magnetic bearings can meet the requirements of tracking position control. In the experiments, the tracking errors were all within 18 μm in the rotating state.
Author(s): X. Guan, J. Zhou, H. Wu, Y. Zhang
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Uncertainty Problem as Illustrated by Magnetotherapy
Abstract: This article presents the impact of fixed tissue conductivities on the distribution of eddy currents in human body. Electrical conductivities characterising human tissues present in limbs have been collated based on various publications from the last 25 years. The article shows the extent to which simulation results are affected by changes to electrical conductivity of specific tissues. It has been demonstrated that the tissues taking the largest part of the studied domain have the greatest impact. The conclusions from these results suggest that it is very important to determine the electrical conductivity of tissues forming the human body with increasing precision, as it is an important factor affecting the accuracy of results. This factor seems much more significant than the growth in the precision of models resulting from increasing resolution of numerical models made available for research purposes.
Author(s): P. Syrek
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Design of Low-Cost, Circularly Polarized, and Wideband U-Slot Microstrip Patch Antenna with Parasitic Elements for WiGig and WPAN Applications
Abstract: In this article, a well matched U-Slot Microstrip Patch Antenna (MPA) with two paratactic elements is designed and simulated. The antenna is designed to resonate at 60 GHz (V-band) and exhibits a wideband extend from 53.3 GHz to 60.8 GHz with more than 87% total efficiency. The presence of U-slot makes a current perturbation in the antenna which contributes to generate a Circular Polarization (CP). The 3-dB Axial Ratio (AR) is extended from 56 – 57.2 GHz (~ 1.2 GHz bandwidth). The analysis and optimization processes throughout this paper are carried out using Finite Element Method (FEM) and verified with Finite Integration Technique (FIT). Good agreement between the results by the two simulators is obtained. Hence, the performance of the proposed antenna makes it a good candidate for fifth generation applications at V-band like Wireless Gigabit Alliance (WiGig) and Wireless Personal Area Network (WPAN).
Author(s): M. S. Ibrahim
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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Title: Computational Analysis for the Combination of Inductive Coupled Wireless Coils and High Permittivity Materials to Improve B1 Field for Rhesus Monkey MRI
Abstract: Magnetic resonance imaging (MRI) scanning of small animals such as non-human primates has been of interest in recent years. Imaging primates, such as rhesus monkeys, presents challenges due to the shape of their head. The shape and dimensions of the head can cause poor magnetic flux density (|B1|) strength and penetration to specific regions of interest. In this study, we focus on the design of an eight-channel, helmet-style array coil for rhesus monkey brain imaging, and performed quantitative analysis by means of electromagnetic (EM) simulations and acquiring reception sensitivity (|B1-|)-fields to demonstrate that the use of combining inductively coupled wireless coils and high permittivity materials can improve the |B1-|-field sensitivity of a tradition phase array coil.
Author(s): D. Hernandez, K.-N. Kim
File Type: Journal Paper
Issue:Volume: 34      Number: 9      Year: 2019
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