ACES Publication Search
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| Title: | ACES Journal May 2013 |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 7706 KB |
| Title: | ACES Journal May 2013 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 605 KB |
| Title: | Plasmonic Enhancement of Irregular Shape Nano-Patch for Thin Film Silicon Solar Cells |
| Abstract: | In this work plasmonic resonance of highly irregular aluminum nanostructures on a silicon photovoltaic substrate is investigated. These structures are inspired by natural surface structuring that occurs during the top-down aluminum induced crystallization of amorphous silicon. The computer simulations are obtained using the Ansys® HFSS allowing studying the enhanced fields transmitted into the silicon layer. The obtained results show significant light trapping and enhancement of the transmitted fields when these nanostructures are composed of high aluminum and low silicon concentration. These effects decrease for lower aluminum and high silicon concentrations cases nanostructures. |
| Author(s): | N. Burford, M. El-Shenawee |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 550 KB |
| Title: | High Accuracy Time Domain Modeling of Microstrip Discontinuities by Using Modified TDR Based on Barker Codes with Flat Spectrum and Integrated Side-Lobes |
| Abstract: | In this paper, a novel time domain method by using a modified time domain reflectometry is presented for high accuracy modeling of microstrip discontinuities. The ordinary stimulus signals used in the TDR technique are voltage step or voltage impulse. In this paper, we propose an alternative technique, whereby a modified excitation pulse based on Barker-Code orthogonal pulses is employed as the stimulus signal in TDR. The advantage conferred by “Barker codes TDR” is that more energy is available at higher frequencies in contrast with conventional step or impulse TDR, and so a higher bandwidth and higher accuracy of the line impedance is achieved. It can also be advantageous when the user is looking for precision in spatial localization, say in a connector or similar in-line structure, as the increased energy at higher frequencies can help. Simulated results are presented to validate the usefulness of the proposed method for calculating the precise amount of time-dependent equivalent circuit of microstrip discontinuity. |
| Author(s): | M. Ojaroudi, E. Mehrshahi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 303 KB |
| Title: | Studying and Analysis of the Characteristic of the High-Order and MRTD and RK-MRTD Schemes |
| Abstract: | In this paper, the stability, dispersion, and convergence of the high-order FDTD (HOFDTD), the multi-resolution time-domain (MRTD), and the Runge-Kutta multi-resolution time-domain (RK-MRTD) schemes are derived, analyzed, and compared. The computational cost and memory requirements of the three methods are also investigated. It is found that the RK-MRTD method is of considerable potential due to its dispersion properties and computational abilities. |
| Author(s): | M. Zhu, Q. Cao, S. Gao |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 270 KB |
| Title: | Study of Penetration Depth and Noise in Microwave Tomography Technique |
| Abstract: | The robustness of the microwave tomography method based on frequency dependent finite difference time domain numerical method and hybrid genetic algorithm for breast cancer imaging for different levels of noise are investigated in this paper. These results indicate the algorithm performs well in the case of data contaminated by various levels of additive white Gaussian noise (up to 15 % of signal strength). Noise levels above this value inhibit the efficacy of the method. |
| Author(s): | A. Sabouni, S. Noghanian2 |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1456 KB |
| Title: | Near Field to Far Field Conversion for an Infinite Ground Micro-Strip Trace Using Genetic Algorithm |
| Abstract: | In this paper, an efficient combination of the near field to far field (NF-FF) transformation and the genetic algorithm (GA) is suggested for investigating of a microstrip trace on an infinite ground plane. Parameters of a set of ideal electric and magnetic dipoles are estimated by GA based on finite samples of near field data in the radiation region. Then, the far field pattern is determined, using the electromagnetic (EM) fields of equivalent ideal dipoles. The commercial software Ansoft High Frequency Structure Simulator (HFSS) is used for both, computing the near field data and validation of the proposed method. In addition, the influence of number of dipoles on the convergence rate is studied. |
| Author(s): | R. Rajabzadeh, G. Moradi |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 352 KB |
| Title: | Through Wall Gap Detection Using Monostatic Radar |
| Abstract: | In this paper, a new experimental system for through wall gap detection and concealed vacancies behind wall is introduced. The ultra wide band (UWB) system is based on the principles of time domain reflectometry (TDR) and ground-penetrating radar (GPR) for through wall imaging to detect hidden gaps and/or hiding persons behind walls. The system uses a very short pulse generated by the vector network analyzer (VNA) to illuminate the wall under investigation through an UWB antenna probe. The detection process is achieved using time domain measurements of the probe reflection coefficient S11. Some numerical analyses have been carried out for verifying the principle of operation. The experimental results show a great ability not only for the gap detection between walls but also for estimation of the gap width with a very good accuracy (6.25 % in the worst case) for different types of walls. |
| Author(s): | A. Elboushi, A. R. Sebak, T. Denidni |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 495 KB |
| Title: | High Selectivity Dual-Band Bandpass Filter with Flexible Passband Frequencies and Bandwidths |
| Abstract: | A short-ended resonator with open stub loaded is presented in this paper. Resonance property is analyzed based on the transmission line theory. Analysis reveals that the odd/even-mode resonance frequency of the proposed resonator can be conveniently controlled. To realize two controllable bandwidths, two different coupling paths are introduced in the filter design. Furthermore, to improve the filter selectivity, the source-load coupling is adopted to create four transmission zeros (TZs) near the edges of the two passbands. Thus, a dual-band bandpass filter (BPF) with high selectivity can be achieved. One filter with two passband frequencies at 1.01 GHz and 2.4 GHz is designed and fabricated to provide an experimental verification on the design method. |
| Author(s): | Y. Ma, W. Che, W. Feng, J. Chen |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 683 KB |
| Title: | A Compact Reconfigurable Antenna Using SIRs and Switches for Ultra Wideband and Multi-Band Wireless Communication Applications |
| Abstract: | In this paper, a novel coplanar waveguide (CPW) fed ultra wideband (UWB) antenna with reconfigurable functions and notch band characteristics is proposed for wireless communication applications. The proposed UWB antenna has two stop bands that are achieved by using the stepped impedance stub (SIS) loaded stepped impedance resonators (SIRs). The reconfigurable functions are obtained by means of two ideal switches that are implemented on the proposed two SIRs. By controlling the status of the ideal switches ON/OFF, the proposed antenna can work in UWB operation band with both switches OFF and the antenna can be used as a dual notch band UWB antenna when the status of both switches is ON. The frequency domain characteristics are investigated, and the time domain characteristics, such as group delay, have been studied in details as well. The simulation and experiment results demonstrate that the proposed reconfigurable antenna can well meet the requirement for the UWB communication, notch band UWB, and multiband communication. |
| Author(s): | Y. Li, W. Li, W. Yu |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 1148 KB |
| Title: | Bandwidth Enhancement of Compact Planar Microstrip Antenna |
| Abstract: | A novel monopole antenna is presented for ultra-wideband (UWB) applications. Enhancement in the antenna’s bandwidth was obtained by using a new radiating patch structure that includes a q-shaped slots in the ground plane. UWB performance is achieved without increasing the overall size of the antenna’s structure. The antenna operates between 2.4 GHz ? 13.9 GHz for S11 ? -10 dB. The antenna radiates omnidirectionally over its operating band. The antenna occupies an area of about 25 × 25 mm2 when fabricated on FR4 substrate with thickness of 1 mm and relative permittivity of Er = 4.4. |
| Author(s): | H. Shirzad, B. Virdee, Ch. Ghobadi, M. Shokri, T. Sedghi, S. Asiaban, J. Pourahmadazar |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 710 KB |
| Title: | Compact Printed Band-Notched UWB Antenna With 90 Degree Rotation Angle CSRR |
| Abstract: | A novel band-notched ultrawideband monopole antenna is presented. The proposed antenna consists of a swallow shape radiating patch, two novel 90 degree rotation angle complementary splitring resonator (CSRR) structures for generating band-notched function instead of changing the patchor feeding shapes, and a trapezoidal ground plane that provides a wide usable bandwidth of more than 143 % (2 GHz – 11.2 GHz). With two novel 90 degree rotation angle complementary SRR structures, band-stop frequency performance is realized, and some key characteristics such as band-notched frequency and bandwidth can be controlled easily. The designed antenna has a small size of 25 × 27.9 mm2?showing the band-rejection performance in the frequency band of 3.9 GHz / 5.9GHz. The antenna demonstrates omni-directional and stable radiation patterns across all the relevant bands. Moreover, a prototype of the proposed antenna is fabricated, and the measured results are shown to be in good agreement with the simulated results. |
| Author(s): | D. Jiang, Y. Xu, R. Xu, W. Lin |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 681 KB |
| Title: | Substrate Integrated Waveguide-Fed Tapered Slot Antenna With Smooth Performance Characteristics Over an Ultra-Wide Bandwidth |
| Abstract: | We present an ultra-wide extended Kband (18 GHz – 30 GHz) planar linear tapered slot antenna (LTSA) design. From a parametric study involving eight designs, the best compromise LTSA is selected in terms of flattest gain and beam width and most symmetric beam width. The design is antipodal with alumina (?r = 10) substrate and fed with substrate integrated waveguide (SIW). Regular corrugations improve cross-polarization, input return loss, and gain. Numerical simulations use finite element analysis and time domain finite integration technique field solvers. The resulting design has half power beam widths (HPBW) of only ± 3.2° and ± 2.5° variation in frequency in the E- and H-planes, respectively. Cross-polarization levels at boresight are 35.7 dB at 18 GHz and 17.4 dB at 30 GHz, return loss is better than -11.7 dB and gain is 9.23 dB with ± 0.40 dB variation with frequency. Alternatively, for imaging systems requiring efficient illumination of a reflector or focusing elements, a second resulting design shows near-perfect beam symmetry with HPBWE/HPBWH = 0.91. These two LTSAs are good candidates for dual-polarization focal plane array feed applications in astronomy imaging. |
| Author(s): | L. S. Locke, J. Bornemann, S. Claude |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 988 KB |
| Title: | Broadband Variable Radial Waveguide Power Combiner Using Multi-Section Impedance Matching Technique |
| Abstract: | An L-band spatial variable radial waveguide power combiner with broad bandwidth and high power capacity is proposed. By adopting several techniques simultaneously, including multi-section impedance matching probes, grounded disc, and axial slots, the performance of the power combiner is improved. The parameters of the combiner are calculated, simulated and tested. It has a measured operation bandwidth ranging from 1.2 GHz to 2 GHz with VSWRs less than 1.4 at all ports. The extra insertion losses between the input ports and output port are less than 0.3 dB and the isolation between the input ports is better than 15 dB. The power capacity can reach 600 W and the combining efficiency achieves 90 %. The results from calculation, simulation, and measurement reasonably agree with each other. |
| Author(s): | G. Xu, X. S. Yang, J. L. Li, Z. M. Tian |
| File Type: | Journal Paper |
| Issue: | Volume: 28 Number: 5 Year: 2013 |
| Download Link: | Click here to download PDF File Size: 337 KB |