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Title: ACES Journal October 2014 Cover
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
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Title: ACES Journal October 2014 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 23 KB

Title: ACES Journal October 2014 Full
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 7164 KB

Title: Earth Conductivity Estimation from Through-the-Earth Measurements of 94 Coal Mines Using Different Electromagnetic Models
Abstract: Through-the-Earth (TTE) communication systems require minimal infrastructure to operate. Hence, they are assumed to be more survivable and more conventional than other underground mine communications systems. This survivability is a major advantage for TTE systems. In 2006, Congress passed the Mine Improvement and New Emergency Response Act (MINER Act), which requires all underground coal mines to install wireless communications systems. The intent behind this mandate is for trapped miners to be able to communicate with surface personnel after a major accident-hence, the interest in TTE communications. To determine the likelihood of establishing a TTE communication link, it would be ideal to be able to predict the apparent conductivity of the overburden above underground mines. In this paper, all 94 mine TTE measurement data collected by Bureau of Mines in the 1970s and early 1980s, are analyzed for the first time to determine the apparent conductivity of the overburden based on three different models: a homogenous half-space model, a thin sheet model, and an attenuation factor or Q-factor model. A statistical formula is proposed to estimate the apparent earth conductivity for a specific mine based on the TTE modeling results given the mine depth and signal frequency.
Author(s): L. Yan, J. Waynert, C. Sunderman
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 589 KB

Title: A Novel Switchable Double Band-Notch Antenna for Ultra-Wideband Application
Abstract: A novel microstrip-fed planar monopole antenna is proposed that is miniaturized in size and provides reconfigurable band-notch properties. The antenna's impedance bandwidth is 150% for VSWR < 2 across 2.6-18.3 GHz, thus satisfying FCC's frequency requirement for UWB systems defined between 3.1-10.6 GHz. To circumvent interference issues resulting from existing nearby communications systems within the UWB operating frequency, the antenna includes an inverted open-loop triangular slot embedded in the hexagonal shaped radiation patch to realize a band-notch response between 3.1 to 3.9 GHz necessary to reject the WiMax band, and open-end resonator structures at both sides of the patch to create a band-notch response between 5.1 to 5.9 GHz, thus enabling band rejection of WLAN and Hyperlink systems. Furthermore, it is demonstrated the band-notch can be electronically controlled without compromising the antenna's characteristic features. This is achieved by strategically located PIN diodes on the antenna.
Author(s): M. N. Moghadasi, S. F. Qotolo
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 753 KB

Title: FDTD-Based Time Reversal Detection for Multiple Targets or Moving Object
Abstract: Based on the Finite-Difference TimeDomain (FDTD) method, this paper presents a novel Time Reversal (TR) algorithm for multiple targets or moving object detection. Two numerical experiments are carried out by the FiniteDifference Time-Domain (FDTD) programs. The results confirm that the proposed TR algorithm could detect multiple targets effectively and track the moving object accurately. The re-focusing waves are very similar with the excitation signal, which can be applied in communications.
Author(s): L. Zhong, R. Zang, J.-S. Hong
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 534 KB

Title: An Investigation of a Wearable Antenna Using Human Body Modelling
Abstract: The work presented is an assay done on the effects of wearable antenna when placed in proximity to the human body. Cloth fabric is used as a substrate to design a planar antenna. Measurement results of the fabricated patch at free space and close to the human body are also presented here. The S11 of the designed antenna when placed close to the body tissue is almost -30 dB and the gain is close to 4 dB. A rectangular three layered human body model is used to evaluate the extent of the effect that the human body has on the parameters that define an antenna like its gain, directivity, etc.
Author(s): E. S. Florence, M. Kanagasabai, G. N. M. Alsath
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 563 KB

Title: Investigation and FDTD Analysis of UWB Microstrip Antenna with Dual Narrow Band-Notched Characteristic
Abstract: In this manuscript, a novel design of Ultra-Wideband (UWB) monopole antenna with dual narrow band-stop performance is proposed. In this design, by using inverted T-shaped slit and T-shaped parasitic structure in the ground plane, additional resonances are excited and much wider impedance bandwidth can be produced; especially at the higher band. In order to generate single and dual band-notched characteristics, we use a pair of protruded E-shaped strips inside the square-ring radiating patch. The measured results reveal that the presented dual band-notched monopole antenna offers a very wide bandwidth form 3.01 GHz to 12.8 GHz with two narrow notched bands, covering 5.2/5.8 GHz to suppress interferences from Wireless Local Area Network (WLAN) system. To verify the validation of proposed antenna, Finite-Difference Time-Domain (FDTD) analysis is investigated. Good return loss, antenna gain and radiation pattern characteristics are obtained in the frequency band of interest. The antenna imposes negligible effects on the transmitted pulses.
Author(s): N. Ojaroudi, M. Mehranpour, Y. Ojaroudi, S. Ojaroudi
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 1037 KB

Title: Triple-Band Microstripline-Fed Printed Wide-Slot Antenna for WiMAX/WLAN Operations
Abstract: A novel triple-band microstrip antenna design is introduced for WiMAX/WLAN applications. The proposed antenna has a moderate size of 38◊39◊0.79 mm3 , yet offers quite well gain performance (5.6-8 dBi) over the operational bands. The antenna consists of a microstrip feedline coupled to a pair of concentric rectangular loops, as well as a split-ring element inserted within a slotted ground plane, which may also be considered as a wide-slot antenna element. In the paper, the numerical antenna design along with the corresponding measurement results is presented. An equivalent circuit modeling of the proposed design along with empirical formulae relating antenna parameters with notch frequencies is also introduced to serve as a useful design guideline.
Author(s): M. H. B. Ucar, Y. E. Erdemli
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 674 KB

Title: Miniaturized Dual-Mode Dual-Band BPF Using a Single Square Patch Loaded Stepped-Impedance Square Open Loop Resonator
Abstract: This letter presents a dual-mode dualband Bandpass Filter (BPF) using a single Square Patch Loaded Stepped-Impedance Square Open Loop Resonator (SPLSISOLR). The first four Transmission Poles (TPs) of SPLSISOLR can be tuned freely. A pair of high-impedance microstrip lines coupled with the resonator are employed to excite these four TPs to build up a dual-mode dual-band BPF, with two TPs in each passbands. The tapped point of the 50 ? feeding lines can be freely sliding on the high impedance microstrip lines, which increases the design freedom of external quality factor of two passbands. To validate the proposed method, a dual-band filter centered at 1.79/5.42 GHz with -3 dB fractional bandwidth of 4.5%/22.5% and compact size of 0.15?g ◊ 0.14?g are designed. The fabricated filter has the merits of high band-to-band isolation, wide stopband, DC block and simple design procedure.
Author(s): J. Xu
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 810 KB

Title: UWB Monopole Antenna with Dual Band-Stop Performance Using G-Shaped SRR and SIR Structures at Feed Line
Abstract: This article presents a new design of ultra-wideband monopole antenna with the characteristics of dual band rejection .The antenna consists of a circular radiating patch, a feed-line with G-shaped Step-Impedance Resonator (SIR) slot and Split-Ring Resonator (SRR) structure, and a ground plane which provides a wide usable fractional bandwidth of more than 120% with two notch bands around 5.15-5.35 GHz and 7.25-7.75 GHz, to avoid interferences from High Performance Radio Local Area Networks (HIPERLAN) and downlink frequency of X-band satellite systems. The simulated and measured results show that the antenna design exhibits an operating bandwidth (VSWR<2) from 2.86 to 12.92 GHz, excluding the rejected bands. The proposed antenna configuration is simple, easy to fabricate and can be integrated into any UWB system. The antenna has an ordinary circular-disc radiating patch, therefore displays good omnidirectional radiation patterns, even at higher frequencies.
Author(s): S. Ojaroudi, Y. Ojaroudi, N. Ghadimi, N. Ojaroudi
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 761 KB

Title: Amplitude-Only Synthesis of Multi-Subaperture Antenna Array by Nonlinear Least-Square Method
Abstract: An improved nonlinear least-square method is presented to the synthesis of multisubaperture antenna array for SAR application. This method changes the traditional nonlinear least-square methodís shortness of being sensitive to its initial value. The whole aperture and the subapertures can generate different radiation beams. Also, the whole aperture and the several subapertures can work simultaneously. The mathematical model of nonlinear least-square method is given and the amplitudes of the array elements are optimized. The Peak Side Lobe Level (PSLL) is controlled effectively. The simulation results show the feasibility and effectiveness of the presented method in the synthesis of array antenna.
Author(s): H. Guo, C.-J. Guo, J. Ding
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 952 KB

Title: Time Domain Analysis of GaAS MESFET Transistors Excited by an Incident Electromagnetic Field
Abstract: A numerical method for the fully distributed modeling of Field Effect Transistor (FET) excited by an incident electromagnetic field using a Finite-Difference Time-Domain (FDTD) method is described. The transistor is modeled using the fully distributed model which consists of a configuration of the conventional equivalent circuit of the transistor and three coupled lines as each distributed element. The distributed source terms represent the coupling with an electromagnetic field in the equation which can be used in the Electromagnetic Interference (EMI) analysis. As a numerical example, the method is applied to a GaAs MESFET and the time domain results are presented.
Author(s): L. Mirzavand, A. Abdipour, R. Mirzavand
File Type: Journal Paper
Issue:Volume: 29      Number: 10      Year: 2014
Download Link:Click here to download PDF     File Size: 637 KB