ACES Publication Search
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| Title: | ACES Journal August 2014 Cover |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 2683 KB |
| Title: | ACES Journal August 2014 Front/Back Matter |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 23 KB |
| Title: | ACES Journal August 2014 Full |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 9087 KB |
| Title: | Method of Moments (MoM) Modeling of Wave Propagation Inside a Wedge |
| Abstract: | Method of Moments (MoM) is used to model guided wave propagation inside a nonpenetrable wedge waveguide and the results are validated against analytical mode-based exact solutions. |
| Author(s): | G. Apaydin, L. Sevgi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 884 KB |
| Title: | Block Matrix Preconditioner for the Coupled Volume-Surface Integral Equation |
| Abstract: | A Block Matrix Preconditioner (BMP) for Volume and Surface Electric Field Integral Equations (V-EFIE and S-EFIE) for the analysis of electromagnetic scattering problems is presented. The V-EFIE operator is well-posed while the S-EFIE operator is ill-posed, so for the coupled V-EFIE and S-EFIE system, it is illconditioned. Therefore, the solution time is very long if the iterative solution is applied to solve the system equations. The proposed scheme constructs a sparse matrix version of each block matrix, which is followed by the inversion of the resultant block sparse matrix using incomplete factorization. The proposed scheme enables the efficient electromagnetic analysis for the composite structures. Several numerical examples are proposed to demonstrate the efficiency of the scheme. |
| Author(s): | S. Tao |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 370 KB |
| Title: | New Ultra-Wideband Phase Shifter Design with Performance Improvement Using a Tapered Line Transmission Line for a Butler Matrix UWB Application |
| Abstract: | A novel design of a compact UltraWideband (UWB) phase shifter with a new stub shape is presented in this paper. The proposed structure is formed using three layers of conductors interleaved with layers of substrates between each of the conductor’s layers. This multilayer technique was proposed to realize a design that is small in size, and a 23 mm × 50 mm compact phase shifter design was accomplished. In addition, the implementation of tapered transmission line techniques improved phase shifter performance, when compared with the conventional design without tapered transmission lines. A parametric study on the tapering of the transmission lines is presented and discussed. The measurement results of the phase shifter satisfactorily agreed with the simulation results. The phase shifters measured results demonstrated ± 5° phase deviation over the UWB frequency range. Moreover, the proposed phase shifter stubs successfully achieved 30% size reduction in comparison with the other available UWB phase shifter. |
| Author(s): | D. N. A. Zaidel, S. K. A. Rahim, N. Seman, R. Dewan, B. M. Sa'ad |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 717 KB |
| Title: | Design of UWB CPW-Fed Slot Antenna with a Band-Stop Notch Using a Parasitic Strip on the Substrate Backside |
| Abstract: | This paper presents a new design of 5.5 GHz band-notched slot antenna fed by a Coplanar Waveguide (CPW) for Ultra-Wideband (UWB) application. By converting a square radiating stub to the stepped structure, a good impedance bandwidth can be achieved, which covers an UWB frequency range. The bandnotched characteristic of this antenna is realized by adding an inverted U-shaped parasitic strip on the other side of antenna substrate. The proposed antenna can operate from 2.85 to 11.93 GHz with a rejection band around 5.02 to 6.13 GHz, to avoid any interference form the Wireless Local Area Network (WLAN) systems. The proposed antenna displays good omni-directional radiation patterns. Simulated and measured results are presented to validate the usefulness of the proposed antenna structure for UWB applications. The designed antenna has a small dimension of 30×30×0.8 mm3 . |
| Author(s): | Y. Ojaroudi, N. Ojaroudi, N. Ghadimi, S. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 805 KB |
| Title: | A Compact Ultra-Wideband Band-Notched Monopole Microstrip Antenna with Modified Complementary Split Ring Resonator |
| Abstract: | A simple and compact microstrip ultra-wideband printed monopole antenna with filtering characteristic is presented. The proposed antenna comprises of a wave ground structure and a swallow radiating patch with co-directional modified pentagon complementary split-ring resonators, which are notched by altering three parameters, respectively. By using a modified wave ground structure, impedance matching characteristic that involves operating frequency band of C-band satellite communication systems and WLAN is obtained. The designed antenna has a compact size of 25×27.9 mm2 and provides the impedance bandwidth of more than 137% from 2.2 GHz to 11.8 GHz, with notch frequency band at 3.59-4.255 GHz, 5.12-5.41 GHz and 5.69-6.03 GHz. The antenna demonstrates omnidirectional 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, T. Huang, Z. He |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1496 KB |
| Title: | Novel Design of Cavity-Backed Slot Antenna by Reformed Ground Plane (Corner Notch and Stepped) and Elongated Mushroom (EM)-EBG |
| Abstract: | A common problem for the performance of a Cavity-Backed Slot (CBS) antenna could be the heavily effect of ground plane. Travelling surface currents on ground plane could cause destructive effect on the characteristics of CBS antenna. This mainly appears on gain back lobe and also Front to Back Ratio (FBR) of pattern. To resolve this problem, the stepped ground plane and the Extended Mushroom Electromagnetic Band-Gap (EM-EBG) structure was introduced, which could minimize ground plane effects by changing the current distribution. Good agreement was achieved between the simulated and measured results. Experimental results showed that on a frequency range over 14-16 GHz, the gain was better than 11 dB and FBR of pattern in the H-plane reached to 26 dB. |
| Author(s): | S. Manshari, M.-N. Azarmanesh |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1125 KB |
| Title: | High Gain, Wideband Aperture Coupled Microstrip Antenna Design Based on Gain-Bandwidth Product Analysis |
| Abstract: | Aperture coupled antennas are studied in terms of Gain-Bandwidth Product (GBWP). To understand whether resonant or non-resonant slot coupled antenna has better performance, several antenna designs with different slot shapes are optimized and compared to each other. Even for a pin-feed microstrip antenna, we show that there exists a substrate height and aspect ratio for optimal GBWP. Based on this analysis, a stacked aperture coupled antenna is designed and optimized for high gain and wideband for Ku band downlink (10.8- 12.75 GHz) applications. The designed antenna exhibits 9.5 dBi broadside gain with 80° half power beam width and almost 30% bandwidth. Ku-band gain ripple is less than 0.5 dB. The antenna is built and measured. Several figure-of-merits based on GBWP have been defined to compare its performance with earlier works. Proposed antenna can be used in demanding high gain, wideband, beam scanning array applications. |
| Author(s): | M. M. Bilgic, K. Yegin |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 1055 KB |
| Title: | Design of UHF RFID Reader Antennas Using Coupled Line Power Divider and Narrow Bandpass Filter |
| Abstract: | In this paper, a Circularly Polarised (CP) universal Ultra-High-Frequency (UHF) RFID reader antenna based on coupled line power divider is firstly proposed. The antenna features compact size, simple structure and low-cost and achieves Return Loss (RL)?25.5 dB, gain?5.5 dBic and Axial Ratio (AR)?1.8 dB, over the universal UHF RFID band of 840 to 955 MHz and the 3-dB AR beam-width is more than 110°. Then, an improved bandpass filter based on coupled lines and a ring resonator is proposed for achieving extremely narrow frequency response. A CP filter reader antenna using this narrow bandpass filter is proposed for enhancing the reliability of the communication and reducing the cost of the microwave front end in RFID system. The filter antenna exhibits the measured 1-dB gain (gain>6.4 dBic) bandwidth from 905 to 930 MHz and RL?15 dB, AR?1.4 dB in the band. |
| Author(s): | Q. Liu, Y. Liu |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 906 KB |
| Title: | Frequency Reconfigurable Monopole Antenna for Multimode Wireless Communications |
| Abstract: | This paper describes a compact reconfigurable microstrip antenna for multimode wireless communications, whose frequency characteristic can be reconfigured electronically to operate at 2.4 GHz (Bluetooth), 3.5 GHz (WiMAX) or 5.2/5.8 GHz (WLAN). The presented microstrip monopole antenna consists of an open-stub microstrip line with two inverted coupled U-shaped parasitic structures and ground plane. Reconfigurability is obtained by implementing two PIN diodes across the antenna structure and biasing these active elements. The proposed antenna can obtain good return loss property with -38 dB at 2.4 GHz, -42 dB at 3.5 GHz and -47 dB at 5.5 GHz. The proposed microstrip antenna fabricated on an FR4 substrate with thickness of 1.6 mm, relative permittivity of 4.4 and has a small size of 12×18 mm2 . The measured return loss characteristics are in good agreement with simulated results, which verified the reliability of the designed antenna. So this new design should have many applications in the circuit where reconfigurable antenna is used. |
| Author(s): | N. Ojaroudi, N. Ghadimi, Y. Ojaroudi, S. Ojaroudi |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 772 KB |
| Title: | Electromagnetic Field and Force Analysis of Three-Phase Enclosure Type GIS Bus Capsule |
| Abstract: | With the aim to optimization design and condition monitoring of Gas Insulation Station (GIS), a 3-D finite element model has been developed for the computation of the electromagnetic field and forces in a three-phase enclosure type GIS bus capsule. The calculation takes into account the bus bar connectors’ contact resistance by modeling equivalent contact bridges between contact interfaces and physical properties of the materials involved have also been considered. Using the field distributions, power losses and electromagnetic forces have been calculated, the calculation is more valid and accurate compared to those from closed-formulas. The influence of the operation current and short current on those quantities is also examined. The results show that the distributions of current density and electromagnetic force in the conductors and tank are not uniform. Electromagnetic force of plug-in connector obtained by closed-formulas calculation has obvious deviation, due to the current distributions are not considered. The electromagnetic forces of bus conductors and plug-in connectors are large enough to overcome hold forces exerted by the contact springs under short circuit conditions. |
| Author(s): | X. Guan, N. Shu |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 858 KB |
| Title: | A Parallel Two-Level Spectral Preconditioner for Fast Monostatic Radar Cross-Section Calculation |
| Abstract: | Although the Multilevel Fast Multipole Method (MLFMM) and the parallel technology can accelerate the matrix-vector product operation, the iteration number does not reduce at all in the iterative solution. A new proposed two-level spectral preconditioning technique is developed for the generalized minimal residual iterative method, in which the MLFMM is used to accelerate the calculation. The Multifrontal Massively Parallel Solver (MUMPS) is used to damp the high frequencies of the error, and the low frequencies of the error are eliminated by a spectral preconditioner in a two-level manner. This technique is a combination of MUMPS and a low-rank updated spectral preconditioner, in which the restarted deflated Generalized Minimal Residual (GMRES) with the newly constructed spectral two-level preconditioner is considered as the iterative method for solving subsequent systems. Numerical experiments indicate that the proposed preconditioner is efficient for the MLFMM and can significantly reduce both the iteration number and computational time. |
| Author(s): | Z. He |
| File Type: | Journal Paper |
| Issue: | Volume: 29 Number: 8 Year: 2014 |
| Download Link: | Click here to download PDF File Size: 453 KB |