ACES Publication Search
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| Title: | ACES Journal January 2019 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2164 KB |
| Title: | ACES Journal January 2019 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 789 KB |
| Title: | ACES Journal January 2019 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 24267 KB |
| Title: | Efficient TLM-Based Approach for Compact Modeling of Anisotropic Materials and Composites |
| Abstract: | Compact modeling approach of anisotropic media by using the Z-TLM method is proposed. Thin anisotropic multilayer material is efficiently described through connection procedure between two Z-TLM mesh cells, by using the scattering parameters to create a digital filter-based compact model. Model is incorporated into non-uniform TLM grid given here in a form fully complying with the originally proposed Z-TLM method algorithm. Accuracy and efficiency of the compact model is confirmed on a few examples through comparison with the fine mesh results. |
| Author(s): | M. D. Kostic, N. S. Doncov, Z. Z. Stankovic, J. D. Paul |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2047 KB |
| Title: | Spatial Partitioning Strategy for Parallelization of MLFMA with Reduced Communication |
| Abstract: | The bottleneck of the spatial partitioning for parallelizing the multilevel fast multipole algorithm (MLFMA) lies in higher levels of the tree, at which boxes are usually fewer than parallel processors, yielding a serious load imbalance. To solve the bottleneck, the higher levels of the tree are truncated to generate plenty of subtrees, which are distributed among processors to facilitate balancing the work load. At the coarsest level, the communication volume during translation between far-away processors is drastically reduced by adopting the far-field approximation. Therefore, the communication mainly occurs between nearby processors, which is favorable for modern computing clusters. In comparison with the parallel strategies that hybridize the spatial partitioning with the k-space partitioning, the proposed approach is more straightforward and shows good scalability. |
| Author(s): | X. Zhao, C. Zhai, Z. Lin, Y. Zhang, Q. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1795 KB |
| Title: | Evaluation of Temperature Elevation in Human Ocular Tissues due to Wireless Eyewear Devices |
| Abstract: | In this paper, a numerical study is proposed to evaluate the temperature variation in the human ocular tissues during the electromagnetic radiation exposure from wireless eyewear device. The results show that the temperature in the whole eyeball increases gradually as the exposure time goes on and could reach the thermal steady state at about 30 minutes. During this process, the temperature increments in different ocular tissues are between 1.1°C and 1.7°C. The results also show the maximal ratio of temperature increments in the initial 5 and 10 minutes to that of the whole steady state could reach to 42.9% and 69.2%, respectively. Therefore, we believe that electromagnetic radiation from wireless eyewear device might pose a threat on the health of the human eyes. People should decrease the talk time as soon as possible to protect their eyes from the possible health hazards. Finally, attention is paid to evaluate the relationship between the maximal SAR and the temperature increments. The results show the temperature increments do not increase in direct proportion to the maximal SAR, which indicates that the maximal SAR and the temperature increments should be taken into account simultaneously while evaluating the biological effect of microwave on the ocular tissues. |
| Author(s): | J. Lan, G. Du |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1913 KB |
| Title: | An Analytical Method for Calculating Radiated Emission of Discontinuous Penetrating Cable |
| Abstract: | Since the interconnection cable between devices is usually much longer than those inside an enclosure, it provides a main gateway for radiated interference. An analytical method for calculating the radiated field of penetrating cable including connectors is proposed based on the cascaded network. This method takes into account the effect of connectors on signal transmission in the calculation model. The discontinuous penetrating cable is regarded as two-port cascaded model which includes three parts: internal cables inside enclosure, connectors and an external cable. The terminal voltage and current of the cable are determined according to terminal conditions, and the current distribution is solved by the transmission line theory. Finally, the electromagnetic radiation of discontinuous penetrating cable is obtained by dipole approximation method. The proposed method is verified by numerical simulation. |
| Author(s): | B.-X. Zhang, P. Xiao, D. Ren, P.-A. Du |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1802 KB |
| Title: | Approximated Solutions on the Electromagnetic Field in Near Zone Generated by a Horizontal Electric Dipole on the Planar Surface of the Anisotropic Rock |
| Abstract: | In this paper, the approximate formulas have been derived for ELF electromagnetic field in near zone from a horizontal electric dipole on the surface of sea water and one-dimensional anisotropic rock boundary. The computational scheme exploits the concept of quasi-static approach for ELF near-field approximations. Specifically, the integrands of Fourier- Bessel representations are approximated by adopting Maclaurin's Expansion where the ratio of wave numbers for rock and sea approaches zero. The approximated solution is in good agreement with the available experimental data. |
| Author(s): | T. Gu, H. Xu, K. Li |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2418 KB |
| Title: | Attenuation in Lossy Circular Waveguides |
| Abstract: | We present a simple closed-form approach to calculate the attenuation of waves in lossy circular waveguides. A set of characteristic equations is first derived by matching the tangential fields at the wall boundary with the constitutive properties of the conducting wall material. In order to represent fields’ penetration into the lossy wall, a perturbation term is then introduced into the equation. We apply the Finite Difference Method to derive the closed-form expression of the perturbation terms for TE and TM modes. The propagation constant can be found by incorporating the perturbation term into the dispersion relation. Our results show good agreement with those obtained from the rigorous transcendental equations. However, unlike the transcendental approach which is usually laborious in solving, our closed-form approach leads to simpler analysis and, therefore, allows the attenuation to be easily computed. |
| Author(s): | K. H. Yeap, E. V. S. Wong, H. Nisar, K. Hirasawa, T. Hiraguri |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1930 KB |
| Title: | Design of Dual-Band Miniaturized Frequency Selective Surface Using Branched Tortuous Structure |
| Abstract: | A miniaturized dual-band frequency selective surface (FSS) is designed by using branched tortuous pattern of cross-dipole element backed by a wire grid of the same periodicity. By introducing the backing wire grid, the metallic line based FSS can provide two pass bands operating at 3.75GHz and 5.88GHz, respectively. The unit size of the proposed FSS is smaller than other similar FSSs and is only 0.075lambda×0.075lambda in size, where lambda is the free-space wavelength at the first resonant frequency. Also, it shows good polarization stability and angular stability. Both simulated and measured results validate the performance. |
| Author(s): | N. Liu, X. Sheng, X. Gao, C. Zhang, D. Guo |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2517 KB |
| Title: | A Varactor Loaded Tunable Dual-band Left-Handed Metamaterial |
| Abstract: | In this paper, we proposed a tunable dual-band left-handed metamaterial (LHM). This dual-band LHM can be regarded as a combination of double-slits split ring resonators (DSSRRs) and rotated ‘H-shape’ structure loaded with varactors. The ‘H-shape’ structure functions like arrayed metallic wires, and is only capable of extracting negative permittivity, but with proper loaded capacitors, it can also extract negative permeability. According to the numerical analysis, such character is closely related to the mutual coupling coefficient. We analyzed both the DSSRRs and the ‘H-shape’ structure through equivalent circuits and simulations, respectively. Later the composed LHM loaded with varactors is also simulated. Dual-band left handed (LH) property can be observed from the retrieved effective parameters, of whom one LH band is stable and wide, approximately from 2GHz to 2.1GHz, while the other one is relatively narrow, shifting from 1.14GHz to 2.36GHz dynamically. Compared to other work where only multi-band technology or tunable method is applied, the combination of both the methods greatly extended the functioning bandwidth. |
| Author(s): | S. Li, W. Yu, A. Z. Elsherbeni, W. Li, Y. Ma |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2200 KB |
| Title: | Analysis of Random Nonuniform Transmission Line Response under Plane-Wave Illumination with a Perturbation Decomposition-Polynomial Chaos Perturbation Decomposition-Polynomial Chaos Expansion Method |
| Abstract: | A perturbation decomposition-polynomial chaos expansion method is presented to evaluate the electromagnetic effects of random nonuniform transmission line under plane-wave illumination. The nonuniformity is represented as perturbation with respect to the reference uniform transmission line. Moreover, by expanding the unknown random parameters in terms of orthogonal polynomials, the stochastic transmission line equation is projected into a set of deterministic transmission line equations. Numerical simulations are presented for several typical deterministic and random nonuniform transmission lines above an ideal ground. The results show that the proposed perturbation decomposition-polynomial chaos expansion method is accurate and computationally efficient compared with the traditional uniform cascaded section method and Monte Carlo method. |
| Author(s): | J. Yang, X. Sun, Y. Zhao, J. Chen, H. Wang |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2789 KB |
| Title: | Radar Target Recognition by Machine Learning of K-Nearest Neighbors Regression on Angular Diversity RCS |
| Abstract: | In this paper, the radar target recognition is given by machine learning of K-NN (K-nearest neighbors) regression on angular diversity RCS (radar cross section). The bistatic RCS of a target at a fixed elevation angle and different azimuth angles are collected to constitute an angular diversity RCS vector. Such angular diversity RCS vectors are chosen as features to identify the target. Different RCS vectors are collected and processed by the K-NN regression. The machine learning belongs to the scope of artificial intelligence, which has attracted the attention of researchers all over the world. In this study, the K-NN rule is extended to achieve regression and is then applied to radar target recognition. With the use of K-NN regression, the radar target recognition is very simple, efficient, and accurate. Numerical simulation results show that our target recognition scheme is not only accurate, but also has good ability to tolerate random fluctuations. |
| Author(s): | K.-C. Lee |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1709 KB |
| Title: | FMCW Chirp Diversity for Mutual Interference Mitigation in Short-range Automotive Radars under Realistic Traffic Model |
| Abstract: | With the worldwide harmonized frequency allocation for automotive radars and increasing rate of modern vehicles equipped with radar systems, mutual interference among automotive radars is becoming a key problem. This paper presents a novel approach for mutual interference mitigation based on diverse waveform design by imposing time and frequency diversity to frequency modulated continuous wave (FMCW) chirp signal considering 79 GHz short-range automotive radar. Performance of the proposed waveform in terms of auto-correlation and cross-correlation has been investigated using software-defined radio (SDR) transceiver and measurement results are provided. The system concept is validated by developing an automotive radar channel model considering a realistic 3D road traffic scenario using a ray-tracing tool. Theoretical analysis and simulation examples of different mutual interference scenarios in an automotive environment are provided to evaluate the effectiveness of the proposed method. Results show that the proposed waveform is able to detect the targets of interest successfully while mitigating the false targets in mutual interference environments. |
| Author(s): | M. A. Hossain, I. Elshafiey, A. Al-Sanie |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2497 KB |
| Title: | Time-Domain Spectral Inversion Method for Characterization of Subsurface Layers in Ground-Penetrating-Radar (GPR) Applications |
| Abstract: | Ground-Penetrating-Radar (GPR) data analysis has been widely utilized in subsurface and geophysics applications. One of the applications turning into great importance is multilayer subsurface hydraulic parameter identification and soil water content estimations. The classic GPR techniques have shown limitations in detecting deeper soil layers and unsatisfactory accuracy in estimating the electrical properties of the layers. Spectral inversion methods have been recently identified and developed to be an effective tool to tackle these problems. In this work, the spectral inversion method is extended in time-domain and a comprehensive formulation of the algorithm along with an improved well-defined cost function is presented. The Time-Domain Spectral Inversion (TDSI) method is then applied to environmentally-relevant multilayer soil geometries and the corresponding estimated electrical properties are drawn. The results show the TDSI method considerably ameliorates the performance of the inversion in terms of simplicity, accuracy, and applicability. |
| Author(s): | Z. Motevalli, B. Zakeri |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2142 KB |
| Title: | Mutual Coupling Reduction Between Patch Antenna and Microstrip Transmission Line by Using Defected Isolation Wall |
| Abstract: | A mutual coupling reduction method for closely installed patch antenna (PA) and microstrip transmission line (MTL) is proposed by means of defected isolation wall structure (DIWS) which is comprised of a metal patch with periodically G-shaped structure and two dielectric substrate sheets set on both sides of the metal patch. The DIWS model, design procedure and investigation on its stop filtering characteristics are presented. Also, the dominant parameters of DIWS are discussed in order to flexibly adjust the stop band to meet the frequency band that we are interested in. Finally, the optimized DIWS is installed on the closely set PA and MTL with a distance of 2 mm to suppress the mutual coupling. The proposed structure is fabricated and measured to verify the simulation results which demonstrated that a high isolation of 27 dB and 37 dB between the antenna and MTL are achieved, respectively. |
| Author(s): | Y. Zhao, Y. Li, W. Shi, W. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1961 KB |
| Title: | A Novel Beam-Steerable Antenna Using HIS-SWG Reconfigurable Artificial Ground Structure |
| Abstract: | An artificial ground structure (AGS) which can be switched between the high-impedance surface (HIS), the surface-waveguide (SWG) and the HIS-SWG hybrid structure is proposed for the design of a beam-steerable antenna. The AGS is reconfigured with PIN diodes inserted on the bottom ground. The antenna radiates a broadside far-field pattern when the AGS is reconfigured into an HIS, and it steers its main beam to the endfire direction when the AGS exhibits as an HIS-SWG hybrid structure. The reconfigured HIS and SWG are analyzed using the Brillouin dispersion theory and the eigenvalue analysis, respectively. A prototype of the proposed beam-steerable antenna is fabricated and measured. The measured results including the reflection coefficients and radiation patterns validate the antenna performance. |
| Author(s): | Y.-F. Cheng, X. Ding, W. Shao, C. Liao |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2196 KB |
| Title: | A Metallic Patch Antenna Using a Simple Short Probe for Improving Impedance Match Bandwidth |
| Abstract: | A metallic patch antenna using double-tuned impedance matching is presented in this paper. The antenna mainly consists of a rectangular ground plane, a radiation patch with U-slot and two short metal cylinders, with a size of 200mm×200mm×25.5mm. The two metal cylinders are used to connect the patch and the ground. With the common effects of the U-slot and the two metal cylinders, the impedance match has become better than before. Moreover, high harmonics and cross polarization are suppressed after loading two short pins. Measured results show that the antenna has a wide impedance bandwidth from 830 MHz to 970 MHz (16%) for voltage standing wave ratio (VSWR) less than 1.5, and a high gain level about 9.3dBi in a wide band. A good agreement is achieved between simulated and measured results. Therefore, the proposed metal antenna is a good choice for UHF RFID applications. |
| Author(s): | Z. Wang, Z. Yang, Y. Yin |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2504 KB |
| Title: | Design of Reconfigurable Ultrawide Band Antenna with Switchable Single/Dual/Triple Band Notch Functions |
| Abstract: | A reconfigurable ultrawide band (UWB) antenna with switchable single, dual, and triple band notch functions is presented in this study. In the proposed structure, by etching slots on the radiating patch, the ground plane, and the feedline, triple band-notched characteristics at the WLAN, WiMAX and X-band frequencies are obtained. Then, by introducing switch modes on the slots, the antenna offers eight working modes and can realize an interconversion between one UWB mode, three single band-notched modes, three dual band-notched modes, and one triple band-notched mode. Simulated and measured results show that the proposed antenna can provide good band-notched functions on the stopbands and has nearly omnidirectional radiation patterns on the passbands. |
| Author(s): | J. Dong, S. Wang, G. Hu |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1973 KB |
| Title: | Design and Optimization of Slotted Micro-Machined Patch Antenna Using Composite Substrate |
| Abstract: | A slotted L-shaped micro-machined patch antenna on composite substrate has been proposed in this article. The slotted patch has been designed on the composite substrate with overall height of 1.675 mm and effective dielectric constant of 3.23. The desired frequency and bandwidth has been achieved by the parametric optimization using Ant Lion optimization technique. The design resonates at 8.1 GHz and 13.5 GHz with the gain of 6 dBi. The simulated and measured results are quite promising. The obtained resonating characteristics of the proposed design are used in the earth exploration satellite services defined by ITU. |
| Author(s): | A. Kumar, A. P. Singh |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1934 KB |
| Title: | Compact Dual-band Hybrid-Fractal MIMO System for UMTS and LTE Mobile Applications |
| Abstract: | This article presents a bandwidth enriched, dual-band, compact, multiple-input-multiple-output (MIMO) antenna with high isolation for UMTS and LTE applications. The proposed coplanar waveguide (CPW)-fed, hybrid fractal MIMO antenna was created by integrating Koch fractal and Sierpinski fractal on a rectangular patch radiator. The MIMO antenna uses a rectangular shaped partial ground plane with a T-shaped stub on the ground plane to improve the isolation between radiators. The iterative technique, using the Koch curve and the Sierpinski square slot fractal was used on the rectangular patch to reduce the size of the MIMO antenna and retain the electrical performance. By using an amalgamated fractal configuration and a CPW feed, a large impedance bandwidth was achieved: 80% wide bandwidth over the operating frequency of 1.81–3.17 GHz with a compact size of 25×35 mm2. The prototype of the optimized MIMO configuration was fabricated using the FR4 substrate, and its characteristics were measured. The proposed antenna resonates at 2.1 and 2.6 GHz. The antenna parameters, including the reflection coefficient (S11, S12, S21, and S22), surface current distributions, realized gain and radiation patterns were simulated and measured. Additionally, the diversity performances of the MIMO antenna were analyzed in terms of diversity gain (DG) and envelope correlation coefficient (ECC). The proposed antenna retains high isolation of less than -20 dB from 1.81–3.17 GHz band; the DG and the ECC are greater than 9.5 dB and less than 0.08, respectively. The peak gains of the proposed antenna are 5.8 dBi and 6.9 dBi at 2.1 GHz and 2.6 GHz, respectively. Hence, the proposed hybrid fractal MIMO antenna is a good candidate for both UMTS and LTE applications. |
| Author(s): | P. Palanisamy, M. Subramani |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1922 KB |
| Title: | Compact Wideband Filtering Power Dividers Based on Short-Circuited Stubs |
| Abstract: | A novel circuit is proposed to design filtering power dividers (FPDs) with bandpass filtering responses and out-of-band rejection performances. The presented circuit is constructed of two transmission line sections, four short-circuited sections and one resistor. Based on the introduced novel circuit, FPD1 is designed by selecting transmission line sections and short-circuited sections as quarter-wave transmission lines. The FPD2 is proposed to realize more compact size, enhanced bandpass selectivity and improved out-of-band rejection performance by replacing the quarter-wave transmission lines in FPD1 with dual transmission lines. The corresponding equations are derived to calculate the initial parameter values of FPD1 and FPD2 by adopting even-odd mode method. For verification, two FPDs centered at 2.0 GHz are designed and fabricated. The measured 3-dB fractional bandwidths of FPD1 and FPD2 achieve up to 63.2% and 52.3%, while the measured rejections with the level better than 20 dB extend to 2.4f0 and 4.0f0, respectively. |
| Author(s): | G. Dong, B. Zhang, W. Wang, Y. Liup |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1898 KB |
| Title: | Spatial Domain Generation of Random Surface Using Savitzky-Golay Filter for Simulation of Electromagnetic Polarimetric Systems |
| Abstract: | A spatial-domain algorithm is introduced for generating both isotropic and anisotropic natural rough surface models with predetermined statistical properties using Savitzky-Golay filter. Unlike the spectral-domain methods, the proposed method does not require the calculation of two-dimensional inverse Fourier transforms which constitute a computational burden for generating large ensembles of high-resolution surfaces. A comparative analysis between the proposed spatial-domain method and one of the conventional spectral-domain methods is presented. The comparison shows that the proposed spatial-domain method results in substantially improved computational performance. The fitness of the generated rough surface to the predetermined statistical properties is verified by calculating a variogram for numerical measurement of the variance and the correlation lengths. To demonstrate the importance of generating such a rough surface for simulation of electromagnetic polarimetric systems, a rough surface with anisotropic statistical properties is placed in the near field region of two antennas of orthogonal polarizations. It is shown that the self and mutual electromagnetic coupling coefficients of the two antennas can be used for measuring the orientation of the rough surface. |
| Author(s): | S. A. M. Soliman, A. E. Farahat, K. F. A. Hussein, A.-E.-H. A. Ammar |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 3159 KB |
| Title: | FEMC Performance of Pyramidal Microwave Absorber using Sugarcane Baggasse and Rubber Tire Dust at 1 GHz to 18 GHz Frequencies |
| Abstract: | The solid, geometrically tapered microwave absorbers are preferred due to their better performance. The goal of this study is to design absorbers that can reduce the electromagnetic reflections to less than -10 dB. Two waste materials of sugarcane bagasse and rubber tire dust in the powder form were used to fabricate independent samples in the pyramidal form. This paper presents the complex permittivity measurements of sugarcane bagasse and rubber tire dust materials. These two materials are found to be potential absorbing materials in microwave frequency to allow absorption of microwave EMI energy. The materials were combined and fabricated in the composite structure. A measurement system using open- ended coaxial probe method was used for characterizing the dielectric properties of the materials in the range of 1 to 18 GHz microwave frequencies. The dielectric property was used to compare the propagation constants of the material. Comparison of the results proved that these two materials have industrial potential to be fabricated as solid absorbers. |
| Author(s): | L. Zahid, M. Jusoh, R.-B. Ahmad, T. Sabapathy, M. F. Malek, M. R. Kamarudin, M. N. Yasin, M. N. Osman |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2231 KB |
| Title: | Role of Surface Geometric Patterns and Parameters in the Dispersion Relations of Spoof Surface Plasmon Polaritons at Microwave Frequency |
| Abstract: | Spoof surface plasmon polaritons (SSPPs) can be excited using geometric shapes on conducting surfaces in microwave (MW) regime. They are eminent as compared to the conventional microstrip (MS) transmission lines, due to their better efficiency and compactness in high density and high-speed circuitry. In this work, we compare normalized dispersion curves (DCs) of different groove shapes engineered on the planar metallic strip with the variation of geometric parameters of the structure, which are obtained by Eigen-mode solver of ANSYS’s HFSS. It is found the dispersion characteristics are determined by the shape and the asymptotic frequency can finely be tuned through the geometric parameters. All DCs deviate further from the light line indicating slow propagation of SSPPS. The performance of rectangular grooves is clearly outstanding; however, the circular grooves behave comparably better than Vee-groove. Further, a low pass plasmonic filter has been proposed with semicircular gradient subwavelength grooves designed on a planar metallic strip with transition sections to match both the impedance and momentum of MS line and the plasmonic waveguide. Results of S-parameters and magnitude of electric field distributions show excellent transmission efficiency from fast guided wave to slow SSPPs. It is also observed that the confinement of such surface waves is dependent on the geometric parameters which can be useful in plasmonic structure engineering and fine-tuning the cutoff frequencies, hence posing a new prospect for advanced plasmonic integrated devices and circuits. |
| Author(s): | R. S. Anwar, L. Mao, H. Ning |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2035 KB |
| Title: | LCP Plane Wave Scattering by a Chiral Elliptic Cylinder Embedded in Infinite Chiral Medium |
| Abstract: | An analytic solution is presented to the scattering of a left circularly polarized (LCP) plane wave from a chiral elliptic cylinder placed in another infinite chiral medium, using the method of separation of variables. The incident, scattered, as well as the transmitted electromagnetic fields are expressed using appropriate angular and radial Mathieu functions and expansion coefficients. The unknown scattered and transmitted field expansion coefficients are subsequently determined by imposing proper boundary conditions at the surface of the elliptic cylinder. Numerical results are presented graphically as normalized scattering widths for elliptic cylinders of different sizes and chiral materials, to show the effects of these on the scattering widths. |
| Author(s): | A.-K. Hamid |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 1664 KB |
| Title: | A Magneto-Rheological Brake Excited by Permanent Magnets |
| Abstract: | In this paper an innovative brake, based on magneto-rheological fluids, is described. A system of Permanent Magnets, properly arranged in the device, has been designed to maximize the excitation field inside the fluid. The system has been analyzed by means of a 3D FEM code. The results in terms of magnetic flux density inside the fluid and the braking torque have been discussed. Furthermore, the magnetic torque necessary to perform the brake actuation has been calculated. Finally, some preliminary measurements on a prototype have been performed. |
| Author(s): | A. Musolino, M. Raugi, R. Rizzo, L. Sani, E. Diez-Jimenez |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2470 KB |
| Title: | A New Compact Finline OMT Based on Multi-Section Transformer |
| Abstract: | In the millimeter wave band, the simplification of the orthomode transducer (OMT)’s structure and processing technic is placed in a more important position. The finline OMT can meet the requirement, but its size is usually not compact enough. To solve this problem, a compact finline OMT based on multi-section transformer is presented. Such OMT can enable size reduction by reasonably designing three transformers to reach the matching condition, which makes the design more flexible. As a result, the -20dB reflection bandwidth of the proposed OMT is 30.2 GHz to 49.8 GHz (49%), while the lengths of main arm’s and side arm’s transition for vertical polarization are 1.35lambdamax and 0.9lambdamax (lamdamax denotes the maximum free space wavelength in band), respectively, which has been greatly reduced compared with the traditional ones. To verify the working performance of the design, a prototype is fabricated and measured. Finally, some assembly errors are analyzed to study its influence. The results show that the proposed OMT can be a good candidate for millimeter wave application. |
| Author(s): | Y. Yu, W. Jiang, S. Zhang, S. Gong, T. Cheng |
| File Type: | Journal Paper |
| Issue: | Volume: 34 Number: 1 Year: 2019 |
| Download Link: | Click here to download PDF File Size: 2314 KB |