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Title: ACES Journal August 2016 Cover
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: ACES Journal August 2016 Front/Back Matter
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: ACES Journal August 2016 Full
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Analysis and Optimization of Elliptic Ridged Waveguide with FDFD Technique and PSO Algorithm
Abstract: A new design technique for elliptic ridged and sectoral waveguides is presented. The PSO technique has been employed, using FDFD to compute the propagation data of the guide. Conflicting requirements of wide bandwidth and high power handling capability are taken both into account with a suitable objective function.
Author(s): A. Fanti, M. Simone, L. Deias
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Comparison between Vector Algorithm and CRSS Algorithms for Indoor Localization using Received Signal Strength
Abstract: A comparison is presented between two indoor localization algorithms using received signal strength, namely the vector algorithm and the Comparative Received Signal Strength (CRSS) algorithm. Signal values were obtained using ray tracing software and processed with MATLAB to ascertain the effects on localization accuracy of radio map resolution, number of access points and operating frequency. The vector algorithm outperforms the CRSS algorithm, which suffers from ambiguity, although that can be reduced by using more access points and a higher operating frequency. Ambiguity is worsened by the addition of more reference points. The vector algorithm performance is enhanced by adding more access points and reference points while it degrades with increasing frequency provided that the statistical mean of error increased to about 60 cm for most studied cases.
Author(s): H. A. Obeidat, Y. A. S. Dama, R. A. Abd-Alhameed, Y. F. Hu, R. Qahwaji, J. M. Noras, S. M. R. Jones
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
Download Link:Click here to download PDF     File Size: 1913 KB

Title: Efficient Stochastic FDTD Algorithm with Optimized GPU Acceleration
Abstract: A 3-D curvilinear stochastic finite-difference time-domain (S-FDTD) technique on modern graphics processing units (GPUs) is introduced in this paper for complex media with high levels of statistically-variable heterogeneities. The novel accelerated methodology develops a robust covariant/contravariant dual-grid tessellation and estimates the mean value and standard deviation of field components during only a single run. In this way, notably accurate and stable estimations can be very rapidly and economically obtained, unlike the usual multiple-realization staircase Monte-Carlo FDTD schemes. These merits are successfully verified via realistic microwave setups with highly-varying media uncertainties, where the featured algorithm is shown to overwhelm the typical exceedingly resource consuming approaches.
Author(s): A. N. Papadimopoulos, G. G. Pyrialakos, N. V. Kantartzis, T. D. Tsiboukis
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
Download Link:Click here to download PDF     File Size: 1946 KB

Title: New Equivalent Circuit Analysis and Synthesis for Broadband Composite Right/Left-Handed Transmission Line Metamaterials
Abstract: This paper proposes a new equivalent circuit analysis and synthesis method for the broadband composite right/left-handed transmission line (CRLH TL) and Dual-CRLH (DCRLH) TL metamaterials. In order to consider magnitude and phase of S-parameter of the CRLH/DCRLH TL element simultaneously, a pseudo-inverse technique is first implemented to extract the primary equivalent circuit. By using the filter synthesis technique, the retrieval primary equivalent circuit is further transformed to a typical band-pass/bandstop filter circuit as the secondary equivalent circuit. With two-step retrieval procedure, the response of the secondary equivalent circuit can more accurately agree with that of CRLH/DCRLH TL unit cell, compared with the sole use of the pseudo-inverse technique or the filter synthesis technique. Based on the equivalent circuit models, the topological structure and parameters of CRLH/DCRLH TL can be effectively synthesized for a given center frequency and bandwidth. Numerical results are given to demonstrate good performance of the proposed analysis and synthesis methods.
Author(s): N. Kou, Y. Shi, L. Li
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Derivation of the Resonant Frequency of Rectangular Dielectric Resonator Antenna by the Perturbation Theory
Abstract: Based on the concept of perturbation theory, a modification to the dielectric waveguide model (DWM) is presented for the calculation of resonant frequency of rectangular dielectric resonator antenna (DRA). A large number of simulations are performed using commercial software and the results are compared between those of the DWM and the proposed method. Finally, the accuracy of proposed method is validated by the experimental data available in the literature. Differences between the measured and theoretical resonant frequencies vary by less than 2%.
Author(s): S. Fakhte, H. Oraizi
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Analytic Expressions of Some Statistics in Radar Target Recognition Based on Late Time Representation
Abstract: In this paper, we consider the projection of the late time response of an unknown radar target onto the column space and the left null space of the matrix whose entries are from the natural frequencies of the specific radar target. We get explicit expressions for the projection onto the column space, the projection onto the left null space, the square of projection onto the column space and the square of the projection onto the left null space. Also, we note that the norm of the defined projection onto the column space and the norm of the defined projection onto the left null space are Ricean distributed, and that the square of the norm of the projection onto the column space and the square of the norm of the projection onto the left null space are chi-square distributed. Accordingly, we give analytic expressions of the mean and the variance of the Ricean distribution and those of the chi-square distribution.
Author(s): J.-H. Lee, Y.-I. Choi, J.-M. Seo, B.-K. Son
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Research on Terahertz Wave Reflection and Transmission of Carbon Nanotubes Slab Using FDTD
Abstract: Terahertz wave reflection and transmission of carbon nanotubes slab are investigated in this paper. The wave and current equations that describe characters of terahertz wave in dispersive carbon nanotubes (CNTs) are presented and discretized by using the auxiliary differential equation (ADE) in the finite-difference timedomain method (FDTD), because the permittivity of CNTs are frequency-dependent. The ADE-FDTD method and programís efficiency is proved by the reference's analytical method. Numerical results show that the transmission coefficient of single wall carbon nanotubes (SWCNTs) does not show distinct peaks and dips at Terahertz frequency. The multiple transmitted pulses of silicon dioxide bi-covered with SWCNTs are observed. The electromagnetic interference (EMI) shielding effect of SWCNTs, double wall carbon nanotubes (DWCNTs) and Hydrogen doped CNTs are compared.
Author(s): M. Y. Wang, H. L. Li, Y. L. Dong, G. P. Li, C. L. Zhong, J. Xu
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Novel Approach of High Resolution Imaging using Modified Excitation Signal for Ground Penetration Radar (GPR) Applications
Abstract: In this paper a modified Gaussian pulse stimulus is employed to improve the accuracy of underground pipe localizing for 2D visualization of GPR results. This pulse shaping puts more energy at higher frequencies in contrast with conventional Gaussian in GPR. Hence, a wider bandwidth is available to achieve higher accuracy for precise spatial localization. Two dimensional simulations of GPR profiles over ground surface with and without conduits run with the finitedifference time-domain (FDTD) program GPRMAX are presented to validate the accuracy of the proposed method. Results from these surveys showed decent structural recovery of a small pipe similar in structure to that of the modeled ones. Finally, the dense surveys served as a benchmark to compare interpretations taken with the same surveys at lower spatial resolutions and profiles with 2D-only processing methods in order to understand errors in analysis and interpretation that are possible from 2D surveys.
Author(s): H. Ebrahimian, M. Ojaroudi, S. Ojaroudi
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Dynamical Chiral Metamaterial with Giant Optical Activity and Constant Chirality Over a Certain Frequency Band
Abstract: We demonstrate numerically and experimentally a dynamical chiral metamaterial that uniaxially creates giant optical activity and circular dichroism. In addition, the structure gives a high negative refractive index due to the large chirality. The proposed chiral metamaterial includes four L attached cross (FLAC) wire strips and offers a simple geometry, flexibility and more efficient results for chiral metamaterial applications such as polarization rotator, EM filter and so on. The experimental results are in a good agreement with the numerical simulation. It can be seen that FLAC wire strips based chiral metamaterial can also be used to achieve natural-small chirality with a constant value in a wide frequency range between 3.5- 4.5 GHz. This is also another crucial feature of the structure. Therefore, the proposed chiral metamaterial with constant chirality value can be used to design novel EM devices such as polarization converter, anti-reflection filters for a certain frequency range.
Author(s): F. Karadag, I. Comez, F. Dincer, M. Bakir, M. Karaaslan
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
Download Link:Click here to download PDF     File Size: 1936 KB

Title: UWB Slot Antenna with Band-Notched Property with Time Domain Modeling based on Genetic Algorithm Optimization
Abstract: This paper presents a kind of band-notched slot antenna with time domain designing method for ultra-wideband (UWB) applications. The proposed antenna consists of a square radiating stub with a defected mircostrip feed-line using an M-shaped step impedance resonator (SIR) slot and a defected ground plane with a pair of inverted U-shaped slots. By cutting two inverted U-shaped slots in the ground plane, a new resonance at the higher frequencies is excited and hence much wider impedance bandwidth can be produced that. To generate a band-notched characteristic, we use an M-shaped slot at the feed-line. The proposed antenna can operate from 3.03 to 13.21 GHz with frequency band-notched function in 7.28-7.79 GHz to avoid interference from downlink of X-band satellite communication systems. To verify the validation of the proposed antenna an equivalent circuit based on time domain reflectometry (TDR) analysis is presented. In addition, the accuracy of the equivalent circuit models have been improved using Genetic algorithm optimization (GAP). Detailed simulation and numerical investigations are conducted to understand their behaviors and optimize for broadband operation. The proposed antenna exhibits almost omni-directional radiation patterns in UWB frequency range and could be used in wireless systems.
Author(s): J. Zolghadr, Y. Cai, N. Ojaroudi
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Novel Wideband End-Fire Conformal Antenna Array Mounted on a Dielectric Cone
Abstract: In this paper, a novel log-periodic antenna named quasi-second order Koch fractal log-periodic dipole array (QLPK2DA) is presented for the conformal applications. The proposed antenna array shows wider operating bandwidth and small physical profile. In addition, the radiation characteristics of the proposed antenna array mounted on a dielectric cone are investigated. Results show that the cone curvature has an influence on the performance of the conformal antenna, both in terms of its bandwidth and radiation patterns. The thickness and permittivity of the dielectric cone have an effect on the bandwidth of the conformal antenna. The measured results show that the antenna has a wide band ranging from 2 GHz to 10 GHz and shows a typical endfire radiation beam. Measurement results of both single antenna and conformal antenna array show a good agreement with simulated values.
Author(s): Z. Li, L. Tan, X. Kang, J. Su, Q. Guo, Y. Yang, J. Wang
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Analysis of Radiation Characteristics of Conformal End-Fire Antenna Mounted on a Large Conducting Cylinder
Abstract: An analysis on the effect of dielectric radome on radiation characteristics of conformal end-fire antenna mounted on a large conducting cylinder is presented in this paper. Ray theory firstly is used to characterize the effect of the planar dielectric layer on the incident electromagnetic wave with different polarizations, which predicts the physical behavior of radome-antenna system. Meanwhile, the paper shows a comparing analysis of the effect of dielectric radome on conformal end-fire antenna with different polarization when the antenna is located on the external surface of a hollow conducting cylinder. It is found that the radiation characteristics of end-fire antenna is significantly changed due to the presence of the dielectric radome, and the effect of dielectric radome on vertically polarized end-fire antenna is less than that on horizontally polarized end-fire antenna. Parametric studies of the proposed radome-antenna system are also presented in this paper to explore the interaction mechanism between the endfire antenna and dielectric radome, and provide brief guidelines for the antenna designers. These results may provide some useful insights in the design of the radome-antenna system in practical engineering.
Author(s): P. Wang
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Low Profile, Broadband Linearly and Circularly Polarized Cavity Backed Antenna Using Halved-Dual Mode SIW Cavity
Abstract: In this paper, a low profile single fed cavity backed slot antenna producing both linear and circular polarizations at two different frequency is presented using a halved dual mode cavity. The proposed antenna has a planar structure using a single layer of printed circuit board (PCB) which allows for integrating the antenna to other planar circuits and provides straight forward connection to SMA connector. One prototype of the antenna is designed and fabricated and very good agreement between measurement and simulation results are obtained. Results show that the proposed antenna is able to present suitable radiation characteristics as both linearly polarized (LP) antenna and circularly polarized (CP) antenna.
Author(s): S. A. Razavi, M. H. Neshati
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Compact Disc-Shaped Printed Antenna Using Parasitic Element on Ground Plane for Super Wideband Applications
Abstract: A microstrip line-fed monopole antenna is proposed and investigated using a structure of parasitic element for super-wideband applications. The parasitic element consists of 4 rectangular embedded slots on the ground plane. This parasitic element on the ground plane leads the UWB frequency band into the SWB frequency band. This proposed monopole antenna is fed by a microstrip line and is printed on low dielectric FR4 material of 1.6 mm thickness. All the simulations are performed using commercially available, finite element method (FEM) based Ansoft high-frequency structure simulator (HFSS) software and CST Microwave Studio. Measured results exhibit that the proposed disc-shaped antenna shows a wide bandwidth which covers from 2.90 GHz to more than 20 GHz, with a compact dimension of 25 mm ◊ 33 mm for VSWR <2, observing an extended ultra-wideband frequency. A good combination is noticed between simulation and measurement. This proposed SWB antenna delivers impedance bandwidth covering the L, C, X, Ku bands and points out sharply surface current flow and nearly omnidirectional radiation patterns, which is appropriate for UWB or SWB applications.
Author(s): M. M. Islam, M. R. I. Faruque, M. T. Islam
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Asymmetrical Single Cell Multiband Uni-Planar Mushroom Resonant Antenna
Abstract: A new asymmetrical zeroth-order resonant antenna with improved efficiency and widened impedance bandwidth is proposed. It comprises a rectangular patch, two shorted stub and coplanar waveguide (CPW) feed to have composite right/left handed (CRLH) features and easy fabrication process. The asymmetry helps to combine three resonance frequencies and extends the bandwidth up to 31%. The efficiency of the proposed antenna is greater than 94% over the entire bandwidth of 4.2 to 6.2 GHz. The proposed antenna has compact size, which can provide omnidirectional radiation pattern suitable for wireless applications. The proposed antenna has also a low frequency miniaturized resonance at GPS standard 1.57 GHz, while the second frequency band covers 802.11a/h/j/n/ac and 802.11p WLAN, dynamic frequency selection (DFS) and transmit power control (TPC) applications.
Author(s): N. Amani, A. Jafargholi
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: A Dual Frequency Monopole Antenna with Double Spurlines for PCS and Bluetooth Applications
Abstract: Design of a simple and compact dual frequency monopole antenna for applications in PCS (Personal Communication System) and Bluetooth system is presented. The first operating frequency is achieved from a traditional monopole antenna structure for the frequency of 1.9 GHz for PCS application while the second operating frequency is obtained from two spurline structures etched on the traditional monopole antenna structure for the frequency of 2.4 GHz for Bluetooth application. Both simulated and experimental results, such as reflection coefficients and VSWR (Voltage Standing Wave Ratio), are presented and discussed. The radiation pattern measurements are also performed. From the measured results, the first operating band covers between 1.851 and 1.98 GHz, and the second operating band covers between 2.28 and 2.53 GHz. The proposed antenna is compact and suitable to be used for applications in the PCS and Bluetooth system.
Author(s): N. Angkawisittpan, A. Siritaratiwat
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Full-Wave Analysis of Indoor Electromagnetic Pollution from Base-Station Antennas
Abstract: Three-dimensional (3D) intricately detailed models for base-station antennas and buildings are created. Indoor radiation from antennas is accurately analyzed using the higher-order basis functions (HOBs) in the context of method of moments (MoM). The use of HOBs reduces the number of unknowns in MoM compared with the use of piecewise Rao-Wilton- Glisson basis functions (RWGs). To significantly improve the capability of MoM, an efficient parallel algorithm is developed based on a block-cyclic matrix distribution scheme. Taking radiation power, mainbeam pointing and materials into account, the electricfield distribution inside buildings is simulated to determine the indoor radiation level, which may be beyond the safety limit. The numerical results are verified through comparison with the measured results.
Author(s): X. Zhao, Z. Lin, H. Zhang, S.-W. Ting, Y. Zhang
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Palladium Decorated SWCNTs Sensor for Detecting Methane at Room Temperature Based on UWB-RFID
Abstract: A chipless sensor in the protocol of ultra wideband radio frequency identification (UWB-RFID) is proposed in the paper. This sensor, used to detect methane at room temperature, is configured by a planar patch antenna plus a U slot on which interdigitated fingers electrodes (IDE) with load of palladium decorated single walled carbon nanotubes (Pd-SWCNTs) are embedded. The sensor can cover the entire UWB spectrum except for the band that produce band-gap. The amplitudes and frequencies of the band-gap are designated as the signatures modulated and reflecting the status quo of methane retrieved by Pd-SWCNTs. The sensor is validated by an approximate combination of the analytical and numerical method. Results show that if the concentration of methane is increased from 0 ppm to 100 ppm at room temperature, the identifiable sensitivity can be achieved by -9.32 dB in terms of the scheme of the amplitude modulation of band-gap frequency; or, the identifiable sensitivity can be achieved by -11.30 dB in terms of the scheme of the frequency modulation of band-gap frequency.
Author(s): J. Liu, P. B. Li
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Transformer-Based Dual-Mode VCO for Multi-Mode Multi-Standard Receiver
Abstract: The proposed VCO in this paper is used for multi-mode multi-standard wireless transceiver. The overall scheme includes two VCOs, each VCO adopts transformer-based structure. On-chip transformer which uses coplanar central tap structure and adopts the top metal winding is present. The primary and secondary inductances adopt octagon differential structure. Electromagnetic field (EM) simulation is carried out by using ADS Momentum. Negative conductance unit adopts the current reuse of cross coupled MOSFET. Oscillation mode can be chosen by switch. The primary and secondary inductances of the transformer are connected with 4 bit binary switches capacitor arrays and varactors under different oscillation modes to extend the range of frequency adjustment. Measurement results show that the frequency range is from 1.2 to 7.3 GHz and the phase noise at 1 MHz offset is less than -80 dBc/Hz in the whole frequency range.
Author(s): X. Fan, X. Shi, L. Tang
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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Title: Design of a 0.7~1.5 GHz Wideband Power Amplifier in 0.18-?m CMOS Process
Abstract: A power amplifier (PA) for multi-mode multi-standard transceiver which is implemented in a TSMC 0.18-?m CMOS process is presented. The proposed PA improves bandwidth using matching compensation, lossy matching network and negative feedback technique. Measurement results show that the working frequency range of the wideband PA is 0.7~1.5GHz, with the maximum output power of 18.2~22.3dBm. The output P1dB during test is 16.6~21.4 dBm, and the corresponding power added efficiency (PAE) is 7.7%~23.4%. The power gain within the working frequency is larger than 16dB and the S11 is less than -13dB. According to the test results, the proposed PA can cover the frequency of more than one octave. The linearity and power gain of the PA is satisfactory within the working frequency.
Author(s): X. Fan, Z. Yu, J. Lu, Z. Hua
File Type: Journal Paper
Issue:Volume: 31      Number: 8      Year: 2016
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