ACES Publication Search
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| Title: | ACES Journal December 2021 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1969 KB |
| Title: | ACES Journal December 2021 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1061 KB |
| Title: | ACES Journal December 2021 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 35710 KB |
| Title: | FDTD Simulations of Modulated Metasurfaces with Arbitrarily Shaped Meta-atoms by Surface Impedance Boundary Condition |
| Abstract: | In this paper, we propose a reducedcomplexity finite difference time domain (FDTD) simulations of modulated metasurfaces with arbitrary unit cells. The three dimensional (3D) physical structure of the metasurface is substituted by a spatially varying surface impedance boundary condition (IBC) in the simulation; as the mesh size is not dictated by sub-wavelength details, considerable advantage in space- and time-step is achieved. The local parameters of the IBC are obtained by numerical simulation of the individual unit cells of the physical structure, in a periodic environment approximation, in the frequency domain. As the FDTD requires an appropriate time domain impulse-response, the latter is obtained by broad-band frequency simulations, and vector fitting to an analytic realizable time response. The approach is tested on metasurface structures with complex unit cells and extending over 10 × 10 wavelengths, using a standard PC with 64GB RAM. |
| Author(s): | Y. Hu, Q. Zhou, X. Fang, M. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1008 KB |
| Title: | Convergence Acceleration of Infinite Series Involving the Product of Riccati–Bessel Function and Its Application for the Electromagnetic Field: Using the Continued Fraction Expansion Method |
| Abstract: | A summation technique has been developed based on the continuous fractional expansion to accelerate the convergence of infinite series involving the product of Riccati–Bessel functions, which are common to electromagnetic applications. The series is transformed into a new and faster convergent sequence with a continued fraction form, and then the continued fraction approximation is used to accelerate the calculation. The well-known addition theorem formula for spherical wave function is used to verify the correctness of the algorithm. Then, some fundamental aspects of the practical application of continuous fractional expansion for Mie scattering theory and electromagnetic exploration are considered. The results of different models show that this new technique can be applied reliably, especially in the electromagnetic field excited by the vertical electric dipole (VED) source in the “earth-ionospheric” cavity. The comparison among the new technology, theWatsontransform, and the spherical harmonic series summation algorithm shows that this new technology only needs less than 120 series items which is already enough to obtain a small relative error, which greatly improves the convergence speed, and provides a new way to solve the problem. |
| Author(s): | Z. Fanghua, D. Qingyun, Y. Zhe, G. Ya |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2668 KB |
| Title: | Design and Analysis of Multi-Mode Distributed Array with Hybrid Optimization Method |
| Abstract: | In this paper, we presented an improved hybrid optimization method to construct distributed array with two identical sub-arrays, which is mainly applied on airplanes as the front-end of communication and detection system. According to different demands on array’s gain and operating distances, the proposed method presents a scheme of implementation of two operate modes by optimizing elements’ positions and excitations. Two sub-arrays are able to work together to realize high gain when the object is quite far away, and one sub-array is able to work alone when the object is relatively close. This method is presented based on Particle Swarm Optimization (PSO) method and convex method, accomplishing that peak sidelobe level (PSLL) of whole array is lowered under -10 dB, and PSLLs of sub-arrays are lowered under -20 dB by supplementing some auxiliary units and re-optimizing array’s excitation distribution. In the procedure of optimization, the hybrid method is designed catering to multiple constraints according to the requirements of practical application. A specific example for synthesizing reconfigurable distributed array is provided and the sensitivity of obtained performance affected by interference of optimized results is discussed. |
| Author(s): | S. Fang, W. Li, W. Ren, Z. Xue |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 8111 KB |
| Title: | Particle Swarm Optimization of Irregular-shaped Hexagon Patch Antenna for 2.4 GHz WLAN Applications |
| Abstract: | This study proposes a patch antenna with an irregular shape on a radiating metal patch for 2.4 GHz WLAN applications. The proposed antenna is optimized using our in-house designed particle swarm optimization (PSO) method. By optimizing the coordinates of each vertex of the hexagon radiating metal patch, the PSO algorithm successfully extends the impedance bandwidth and antenna gain without increasing the size, cost, and complexity of the antenna. The optimized antenna has a unique and irregular shape. Measured impedance bandwidth of 7.71% (2.37–2.56 GHz) and peak gain of 2.84 dBi of the proposed irregular-shaped patch antenna are obtained. The simulated and measured results of reflection coefficient, gain, and far-field radiation are found to be in good agreement with each other, hence evidently confirming the validity of the proposed method. The proposed irregular shaped hexagon patch antenna demonstrates superior performance of impedance bandwidth and antenna gain compared to those of the regularshaped hexagon patch antenna. |
| Author(s): | W.-C. Weng, M.-C. Chang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 745 KB |
| Title: | Equivalent Circuit Approximation to the Connector-Line Transition at High Frequencies using Two Microstrip Lines and Data Fitting |
| Abstract: | This article presents a method of obtaining an equivalent lumped element circuit to model the electrical connector-line transitions in the ultra-high frequency (UHF) band. First, the scattering matrices of two microstrip transmission lines that are otherwise identical but have the physical lengths of d and 2d are measured. Next, the theoretical model of the lines cascaded with the connector-line transitions modeled as lumped element circuits is established. The selection of the line lengths to be d and 2d results in an over determined system of equations that links the circuit component values to the two-port network parameters of the cascaded system. Finally, the least-squares data fitting procedure yields the best-fit component values. The results show that in our tested scenario, 3-component reactive circuit models well the transitions. Compared with the previous methods, the proposed approach does not require knowledge of the dielectric properties of the substrate of the measured transmission lines. This property integrates the method with our previous work on estimating a microstrip line substrate’s relative permittivity and loss tangent. The obtained transition circuit model is also validated through the testing of two quarter-wave transformers. The lines and transformers are implemented on a textile substrate to highlight the method’s applicability to wearable textile-based electronics. |
| Author(s): | D. Le, N. Pournoori, L. Sydanheimo , L. Ukkonen, T. Bjorninen |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 822 KB |
| Title: | Linear Antenna Array Synthesis by Modified Seagull Optimization Algorithm |
| Abstract: | This paper presents a study of linear antenna array (LAA) synthesis with a seagull optimization algorithm (SOA) to achieve radiation patterns having low maximum sidelobe levels (MSLs) with and without nulls. The SOA is a new optimization technique based on the moving and attacking behaviors of the seagull in the nature. In this study, the original mathematical model of SOA is modified by compensating the exploration and exploitation features to improve the optimization performance. The optimization ability of the modified SOA (MSOA) is tested with seven numerical examples of LAA. In the first three examples, the amplitude values of the array elements are optimized by MSOA whereas the element position values are calculated by MSOA for the last four examples. The numerical results obtained by MSOA are compared with those of different algorithms from the literature. The results reveal that MSOA algorithm is very good at optimizing antenna array parameters to obtain a desired radiation pattern. Additionally, it is seen that MSOA finds better results than the compared algorithms in terms of MSL and single and multiple null depth levels (NDLs). The contribution of the modification of MSOA is shown with a convergence curve to compare with the original one. |
| Author(s): | E. Kurt, S. Basbug, K. Guney |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 6625 KB |
| Title: | Pattern Analysis of Conformal Antenna Arrays via the Characteristic Modes of Isolated Elements |
| Abstract: | A simple pattern analysis method is presented for conformal antenna arrays, considering mutual coupling effects based on the characteristic modes of isolated elements. There are many methods to analyze the performance of conformal antenna arrays, but they seldom provide a clear insight into the coupling mechanism. Thus, the overall characteristic modes of the conformal array are calculated from the characteristic modes of the isolated elements and coordinate transformation, which are different from the traditional modal analysis for the entire array. And the radiation field of the conformal array is given. The modal coupling matrix which depends on the structural parameters and relative pose of conformal elements is used to characterize the mutual coupling effect between elements and explain the coupling mechanism from the perspective of the characteristic currents. Finally, the effectiveness and efficiency of the proposed method is verified by some numerical examples. |
| Author(s): | Y. Zeng, S. Zhang, S. Lou |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 557 KB |
| Title: | Dual-Band Folded Monopole MIMO Antennas with Enhanced Isolation |
| Abstract: | In this paper, a compact dual-band multipleinput multiple-output (MIMO) diversity antenna is proposed. Each of the two MIMO antennas consists of two folded strips working as radiating elements that are fed by a microstrip line. The antennas operate in three WLAN bands: ISM 2.45 GHz, 5.25 GHz, and ISM 5.775 GHz. To improve the isolation at WLAN (2.4–2.48 GHz), two L-shaped slots are etched in the ground plane while a U-shaped slot is cut in the ground plane to enhance isolation at WLAN (5.15–5.35 GHz and 5.725–5.825 GHz). Three slots on the substrate between radiating patches are also employed for an extra reduction in the mutual coupling at 2.45 GHz. The antenna performance was examined by simulation employing CST Microwave Studio Software. The proposed antenna offers minimum isolation of more than 19.5 dB, a low envelope correlation coefficient (ECC) of less than 0.0016, and good radiation efficiency (~880%) through the operating frequency bands. The antenna is compact, thin, and suitable for portable devices. |
| Author(s): | L. S. Yahya, L. S. Yahya, K. H. Sayidmarie |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1534 KB |
| Title: | A Compact Dual-band Planar Antenna Loaded with Magneto Dielectric Ferrite |
| Abstract: | In this paper, a compact dual-band planar antenna loaded with magnetodielectric ferrite is proposed for ISM/GSM/UMTS. Slot and ring structures are dual-resonant mode generators of the antenna. And the characteristic mode analysis is used for the modeling, analysis, and optimization of the proposed antenna. Because of the loading of a piece of rectangular Co2W hexaferrite medium, this antenna can be used in lower frequency bands. The electromagnetic parameters of this ferrite are measured by the transmission line method. Finally, the antenna is fabricated and measured. The operation frequency band (S11<–10 dB) is determined to be 80 MHz (890–970 MHz) and 370 MHz (1.87–2.24 GHz) with the dual resonance frequencies of 925 MHz and 2.175 GHz, respectively, which is capable for ISM (915 MHz)/GSM900/UMTS applications. |
| Author(s): | Y. Li, Q. Feng, Z. Zheng |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 6261 KB |
| Title: | A Gain-enhanced Dual-band Microstrip Antenna using Metasurface as Superstrate Configuration |
| Abstract: | In this paper, antenna gain enhancement using a metasurface (MS) which is designed over the FR4 dielectric by introducing a periodic arrangement of unit cells on a microstrip patch antenna is presented. Combined with the theoretical proof, a method of loading low-frequency MS structure on microstrip antenna is proposed and the antenna gain is improved by using the superposition principle of electric field above the antenna. The proposed antenna is fabricated and measured. It achieves a 4.49 dBi gain enhancement and 8.27 dBi gain enhancement when the superstrate is added over the microstrip antenna at the design frequency of 2.4 GHz and 1.8 GHz, respectively. Since there are a large number of electromagnetic waves in this frequency band in the environment, it can be extended to the study of RF energy collection and other aspects. |
| Author(s): | H.-Q. Tian, J.-L. Wang, D. Han, X. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1269 KB |
| Title: | Design Optimization of Ultra-Wideband Vivaldi Antenna using Artificial Intelligence |
| Abstract: | In this work, computationally efficient design optimization of frequency selective surface (FSS)-loaded ultra-wideband Vivaldi antenna via the use of datadriven surrogate model is studied. The proposed design methodology consists of a multi-layer FSS structure aimed for performance improvement of the Vivaldi design, which makes the design a multi-objective multidimensional optimization problem. For having a fast and accurate optimization process, a data-driven surrogate model alongside the metaheuristic optimizer honeybee mating optimization (HBMO) had been used. The optimally designed antenna had been prototyped and its performance characteristics had been measured. The obtained experimental results are compared with the simulated results of the proposed method. Results show that the obtained FSS-loaded structure has enhanced directivity compared with the design without FSS structure, without any performance losses in the return loss characteristics. The FSS-loaded Vivaldi antenna operates at 2–12 GHz band with a maximum gain of 10 dBi at 10 GHz which makes the design a good solution for RADAR applications. |
| Author(s): | P. Mahouti, A. Kızılay, O. Tari, A. Belen, M. A. Belen, A. Caliskan |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 2647 KB |
| Title: | Dual-Band Phased Array 5G Mobile-Phone Antenna with Switchable and Hemispherical Beam Pattern Coverage for MIMO-Diversity Communications |
| Abstract: | A new design of dual-band antenna array with 3D-coverage beam steering characteristic for millimeterwave (MM-Wave) communications is proposed in this manuscript. The antenna covers frequency bands of 18 GHz and 28 GHz. Its configuration contains three subarrays of patch radiators along the edge area of the smart phone printed circuit board (PCB). Each sub-array contains eight elements of dual-band patch antennas with C-shaped slots. The resonant frequencies of the single element radiator can be adjusted by tuning the sizes of the embedded C-shaped slot and the main patch radiator. The beam-steerable antenna is designed on an N9000 PTFE dielectric. In order to achieve high gain beams and also for covering wider beam-steering area, each sub-array is deployed in different top-sides of the PCB with a dimension of 55×110 mm2. Using three uniform linear eight element sub-arrays, hemispherical beam pattern coverages can be achieved. The proposed antenna provides good performances in terms of gain, radiation and total efficiencies, and beam steering properties which make it suitable for use in the fifth generation (5G) mobile-phone platforms. |
| Author(s): | N. O. Parchin, O. M. Dardeer, A. S. I. Amar, C. H. See, R. Abd-Alhameed |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 1200 KB |
| Title: | Design of Planar Directional Coupler using 2-Bit Fragment Structures |
| Abstract: | Automatic design of planar directional coupler can be implemented by multi-objective optimization searching for the optimal planar fragment-type structure (FTS). The 2-bit FTS description scheme may include necessary fine structures in fragments to enhance the FTS design. By coding the coupler design space on PCB in 2-bit FTS, defining the FTS design matrix, and searching for the optimal structure, directional coupler can be designed without any structure presetting or artificial intervention. The scheme is demonstrated by designing 10-dB wideband directional coupler with 2-bit FTS scheme. The designed directional couplers are fabricated and tested to show maximum directivity of 58 dB with 36% operation bandwidth. |
| Author(s): | Y. Tao, W. Zhang, J. Siden, G. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 527 KB |
| Title: | Compact Dual-Band Bandpass Filter Based on SSL-SIR With Sharp Roll-Off |
| Abstract: | A compact dual-band bandpass filter (DBBPF) is studied and implemented by using shorted stub-loaded stepped impedance resonator (SSL-SIR) and 0º feed structure in this paper. The resonance frequencies of SSL-SIR can be analyzed and explained by odd-even mode analysis method and it is used in the design of BPF I. Then, the BPF II is created using the theory of 0ºfeed structure. Finally, the two structures are combined together to form a DB-BPF by reasonably adjusting the coupling between them and the position of the feed points. The simulation results suggest that the center frequencies of the two passbands are 3.45 and 5.2 GHz, respectively, which are suitable for modern wireless communication systems like 5G and WLAN. Compact size, strong passband isolation, and large stopband bandwidth are all advantages of the proposed DB-BPF filter. A prototype is created and constructed to validate this. The simulated results are in good agreement with the measured results. |
| Author(s): | J. Yue, G. Zhang, Z. Che, Y. Lun, Z. Li, J. Suo |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 4496 KB |
| Title: | Power Changes of Electromagnetic Waves Across the Temporal Boundary in Simple Polar-Molecule Reactions |
| Abstract: | Microwave-assisted chemical reactions have been widely used, but the inhomogeneous heating limits further applications. The aim of this paper is to investigate the power transfer behavior in the simple polarmolecule reactions whose polarization changes with the proceeding of the reactions. At the temporal boundary, based on the continuity of charge and flux and the equivalent transmission line approach of the simple polarmolecule reactions, we discover the power changes in the reactions. The numerical results are in agreement with the theory of the temporal boundary. When the time scale of the component concentration variation is smaller than the wave period, the polarization is not continuous at the temporal boundary. The impedance of the reactions across the temporal boundary changes, and the reflection occurs. Moreover, when the dielectric property of the reactions decreases, the power of the waves increases after the temporal boundary and the waves experience a net energy gain. The results may be helpful in disclosing the non-uniform electromagnetic energy distribution in chemical reactions. |
| Author(s): | X. Liu, S. Zhang, K. Huang |
| File Type: | Journal Paper |
| Issue: | Volume: 36 Number: 12 Year: 2021 |
| Download Link: | Click here to download PDF File Size: 857 KB |