Vol. 143
Latest Volume
All Volumes
PIER 179 [2024] PIER 178 [2023] PIER 177 [2023] PIER 176 [2023] PIER 175 [2022] PIER 174 [2022] PIER 173 [2022] PIER 172 [2021] PIER 171 [2021] PIER 170 [2021] PIER 169 [2020] PIER 168 [2020] PIER 167 [2020] PIER 166 [2019] PIER 165 [2019] PIER 164 [2019] PIER 163 [2018] PIER 162 [2018] PIER 161 [2018] PIER 160 [2017] PIER 159 [2017] PIER 158 [2017] PIER 157 [2016] PIER 156 [2016] PIER 155 [2016] PIER 154 [2015] PIER 153 [2015] PIER 152 [2015] PIER 151 [2015] PIER 150 [2015] PIER 149 [2014] PIER 148 [2014] PIER 147 [2014] PIER 146 [2014] PIER 145 [2014] PIER 144 [2014] PIER 143 [2013] PIER 142 [2013] PIER 141 [2013] PIER 140 [2013] PIER 139 [2013] PIER 138 [2013] PIER 137 [2013] PIER 136 [2013] PIER 135 [2013] PIER 134 [2013] PIER 133 [2013] PIER 132 [2012] PIER 131 [2012] PIER 130 [2012] PIER 129 [2012] PIER 128 [2012] PIER 127 [2012] PIER 126 [2012] PIER 125 [2012] PIER 124 [2012] PIER 123 [2012] PIER 122 [2012] PIER 121 [2011] PIER 120 [2011] PIER 119 [2011] PIER 118 [2011] PIER 117 [2011] PIER 116 [2011] PIER 115 [2011] PIER 114 [2011] PIER 113 [2011] PIER 112 [2011] PIER 111 [2011] PIER 110 [2010] PIER 109 [2010] PIER 108 [2010] PIER 107 [2010] PIER 106 [2010] PIER 105 [2010] PIER 104 [2010] PIER 103 [2010] PIER 102 [2010] PIER 101 [2010] PIER 100 [2010] PIER 99 [2009] PIER 98 [2009] PIER 97 [2009] PIER 96 [2009] PIER 95 [2009] PIER 94 [2009] PIER 93 [2009] PIER 92 [2009] PIER 91 [2009] PIER 90 [2009] PIER 89 [2009] PIER 88 [2008] PIER 87 [2008] PIER 86 [2008] PIER 85 [2008] PIER 84 [2008] PIER 83 [2008] PIER 82 [2008] PIER 81 [2008] PIER 80 [2008] PIER 79 [2008] PIER 78 [2008] PIER 77 [2007] PIER 76 [2007] PIER 75 [2007] PIER 74 [2007] PIER 73 [2007] PIER 72 [2007] PIER 71 [2007] PIER 70 [2007] PIER 69 [2007] PIER 68 [2007] PIER 67 [2007] PIER 66 [2006] PIER 65 [2006] PIER 64 [2006] PIER 63 [2006] PIER 62 [2006] PIER 61 [2006] PIER 60 [2006] PIER 59 [2006] PIER 58 [2006] PIER 57 [2006] PIER 56 [2006] PIER 55 [2005] PIER 54 [2005] PIER 53 [2005] PIER 52 [2005] PIER 51 [2005] PIER 50 [2005] PIER 49 [2004] PIER 48 [2004] PIER 47 [2004] PIER 46 [2004] PIER 45 [2004] PIER 44 [2004] PIER 43 [2003] PIER 42 [2003] PIER 41 [2003] PIER 40 [2003] PIER 39 [2003] PIER 38 [2002] PIER 37 [2002] PIER 36 [2002] PIER 35 [2002] PIER 34 [2001] PIER 33 [2001] PIER 32 [2001] PIER 31 [2001] PIER 30 [2001] PIER 29 [2000] PIER 28 [2000] PIER 27 [2000] PIER 26 [2000] PIER 25 [2000] PIER 24 [1999] PIER 23 [1999] PIER 22 [1999] PIER 21 [1999] PIER 20 [1998] PIER 19 [1998] PIER 18 [1998] PIER 17 [1997] PIER 16 [1997] PIER 15 [1997] PIER 14 [1996] PIER 13 [1996] PIER 12 [1996] PIER 11 [1995] PIER 10 [1995] PIER 09 [1994] PIER 08 [1994] PIER 07 [1993] PIER 06 [1992] PIER 05 [1991] PIER 04 [1991] PIER 03 [1990] PIER 02 [1990] PIER 01 [1989]
2014-02-10
PIER
Vol. 143, 821-848, 2013
download: 275
Developing One-Dimensional Electronically Tunable Microwave and Millimeter-Wave Components and Devices Towards Two-Dimensional Electromagnetically Reconfigurable Platform (Invited Paper)
Sulav Adhikari and Ke Wu
An overview of state-of-the-art frequency tunable technologies in the realization of tunable radio frequency (RF) and microwave tunable circuits is presented with focus on filter designs. Those enabling techniques and materials include semiconductors, micro-electro-mechanical systems (MEMS), ferroelectric and ferromagnetic materials. Various performance indicators of one-dimensional tunable filters are addressed in terms of tunability, losses, signal integrity and other aspects. Fundamental limitations of the classical onedimensional tuning method are discussed, which makes use of only one type of tunable elements such as either electric or magnetic tuning/controlling of circuit parameters. Requirements of simultaneous electric and magnetic two-dimensional tuning techniques are highlighted for achieving an unprecedented and advantageous wider modal tuning. It is believed that this emerging scheme will lead its way in the realization of future highly efficient and tunable RF and microwave components and devices.
DEVELOPING ONE-DIMENSIONAL ELECTRONICALLY TUNABLE MICROWAVE AND MILLIMETER-WAVE COMPONENTS AND DEVICES TOWARDS TWO-DIMENSIONAL ELECTROMAGNETICALLY RECONFIGURABLE PLATFORM (Invited Paper)
2014-01-27
PIER
Vol. 143, 773-819, 2013
download: 570
Silicon Multimode Photonic Integrated Devices for on-Chip Mode-Division-Multiplexed Optical Interconnects (Invited Review)
Daoxin Dai , Jian Wang and Sailing He
In order to enhance the capacity of an optical-interconnect link with a single wavelength carrier, multimode spatial-division multiplexing (SDM) technology has been attracted lots of attention. For a mode-multiplexed optical-interconnect link, the functionality elements become quite different from the conventional ones because multiple modes are involved. In this paper we give a review and discussion on multimode photonic integrated devices for mode-multiplexed optical-interconnect. First light propagation and mode conversion in tapered waveguides as well as bent waveguides is discussed. Recent progresses on mode converter-(de)multiplexers are then reviewed. The requirement of some functionality devices used for mode-multiplexed optical-interconnects is also discussed. In particular, the fabrication tolerance is analyzed in detail for our hybrid demultiplexer, which enables mode-/polarization-division-(de)multiplexing simultaneously.
SILICON MULTIMODE PHOTONIC INTEGRATED DEVICES FOR ON-CHIP MODE-DIVISION-MULTIPLEXED OPTICAL INTERCONNECTS (Invited Review)
2014-01-25
PIER
Vol. 143, 761-771, 2013
download: 289
Localized Monochromatic and Pulsed Waves in Hyperbolic Metamaterials (Invited Paper)
Ioannis Besieris and Amr M. Shaarawi
A special class of metamaterials known as hyperbolic media allow the propagation of large classes of novel monochromatic and pulsed localized waves. Illustrative explicit solutions are given of ``accelerating'' oblique Airy beams, as well as nondiffracting and nondispersive spatiotemporally localized ``all-speed'' X-shaped and MacKinnon-type waves.
LOCALIZED MONOCHROMATIC AND PULSED WAVES IN HYPERBOLIC METAMATERIALS (Invited Paper)
2014-01-17
PIER
Vol. 143, 745-760, 2013
download: 247
Differential Forms Inspired Discretization for Finite Element Analysis of Inhomogeneous Waveguides (Invited Paper)
Qi Dai , Weng Cho Chew and Li Jun Jiang
We present a differential forms inspired discretization for variational finite element analysis of inhomogeneous waveguides. The variational expression of the governing equation involves transverse fields only. The conventional discretization with edge elements yields an unsolvable generalized eigenvalue problem since one of the sparse matrix is singular. Inspired by the differential forms where the Hodge operator transforms 1-forms to 2-forms, we propose to discretize the electric and magnetic field with curl-conforming basis functions on the primal and dual grid, and discretize the magnetic flux density and electric displacement field with the divergence-conforming basis functions on the primal and dual grid, respectively. The resultant eigenvalue problem is well-conditioned and easy to solve. The proposed scheme is validated by several numerical examples.
DIFFERENTIAL FORMS INSPIRED DISCRETIZATION FOR FINITE ELEMENT ANALYSIS OF INHOMOGENEOUS WAVEGUIDES (Invited Paper)
2014-01-03
PIER
Vol. 143, 709-743, 2013
download: 259
Three-Parameter Elliptical Aperture Distributions for Sum and Difference Antenna Patterns Using Particle Swarm Optimization (Invited Paper)
Arthur Densmore and Yahya Rahmat-Samii
This paper presents a unified analysis of the three-parameter aperture distributions for both sum and difference antenna patterns, suitable for communications or telemetry applications with either a stationary or tracking antenna, and with the parameters automatically determined by Particle-Swarm Optimization (PSO). These distributions can be created, for example, by reflector, phased array, or other antenna systems. The optimizations involve multiple objectives, for which Pareto efficiency concepts apply, and are accelerated by compact, analytical closed-form equations for key metrics of the distributions, including the far-field radiation pattern and detection slope of the difference pattern. The limiting cases of the threeparameter distributions are discussed and shown to generalize other distributions in the literature. A derivation of the generalized vector far fields provides the background for the distribution study and helps clarify the definition of cross-polarization in the far-field. Examples are given to show that the three-parameter (3P) distributions meet a range of system-level constraints for various applications, including a sidelobe mask for satellite ground stations and maximizing pointing error detection sensitivity while minimizing clutter from sidelobes for tracking applications. The equations for the relative angle sensitivity for the difference pattern are derived. A study of the sensitivity of the 3P parameter values is presented.
THREE-PARAMETER ELLIPTICAL APERTURE DISTRIBUTIONS FOR SUM AND DIFFERENCE ANTENNA PATTERNS USING PARTICLE SWARM OPTIMIZATION (Invited Paper)
2013-12-11
PIER
Vol. 143, 675-708, 2013
download: 371
Microwave Imaging Within the Interval Analysis Framework
Paolo Rocca , Matteo Carlin , Luca Manica and Andrea Massa
An approach based on the use of the arithmetic of intervals and Interval Analysis for the solution of inverse scattering problems is presented and assessed. By exploiting the property of the Interval Analysis to find the global minimum of a functional in a n-dimensional space, the proposed approach adopts a branch and bound process to discard the regions of the solutions space not containing the global solution, while keeping those where a feasible solution is expected until a suitable converge criterion is reached. A representative set of results concerned with the reconstruction of circular dielectric objects within the first-order Born approximation are reported and discussed to show potentialities and current limitations of the proposed approach.
MICROWAVE IMAGING WITHIN THE INTERVAL ANALYSIS FRAMEWORK
2013-12-10
PIER
Vol. 143, 641-673, 2013
download: 290
Minimum q for Lossy and Lossless Electrically Small Dipole Antennas (Invited Paper)
Arthur D. Yaghjian , Mats Gustafsson and Lars Jonsson
General expressions for the quality factor (Q) of antennas are minimized to obtain lower-bound formulas for the Q of electrically small, lossy or lossless, combined electric and magnetic dipole antennas confined to an arbitrarily shaped volume. The lower-bound formulas for Q are derived for the dipole antennas excited by both electric and magnetic surface currents as well as by electric surface currents alone. With either excitation, separate formulas are found for the dipole antennas containing only lossless or nondispersive-conductivity material and for the dipole antennas containing highly dispersiveconductivity material. The formulas involve the quasi-static electric and magnetic polarizabilities of the associated perfectly conducting volume of the antenna, the ratio of the powers radiated by the electric and magnetic dipoles, and the efficiency of the antenna.
MINIMUM Q FOR LOSSY AND LOSSLESS ELECTRICALLY SMALL DIPOLE ANTENNAS (Invited Paper)
2013-12-06
PIER
Vol. 143, 623-639, 2013
download: 256
Numerical Modelling of Human Body for Bluetooth Body-Worn Applications
Masood Ur-Rehman , Qammer Hussain Abbasi , Xiaodong Chen and Zhinong Ying
The human body has got a pivotal role in portable devices operating in Body-centric Wireless Networks (BCWNs). Electromagnetic interaction between lossy human body tissues and wearable antennas degrades the system performance. Efficient deployment of such systems necessitates thorough understanding of these effects. Numerical analysis is a powerful tool that provides useful information of such scenarios fairly quicker than the actual measurements giving the user full control of the design environment. This paper investigates usefulness of numerical analysis based on the comparison of three different homogeneous models of the human body. Effectiveness of a numerical model is evaluated in terms of its resolution, computational efficiency, time consumption and accuracy of the results in software followed by experimental verifications.
NUMERICAL MODELLING OF HUMAN BODY FOR BLUETOOTH BODY-WORN APPLICATIONS
2013-12-06
PIER
Vol. 143, 605-621, 2013
download: 309
A Study of Radar Features of Wind Turbines in the HF Band
Aale Naqvi and Hao Ling
Radar features of wind turbines are simulated and studied in the HF band. The features are presented in the range-Doppler plane for single as well as arrays of turbines. Doppler aliasing due to the limited pulse repetition frequency of HF radars is examined. Shadowing characteristics of arrays of turbines are simulated and analyzed. Electromagnetic modeling details including effects of thin-wire modeling, non-conducting turbine components, and the presence of a conducting ground surface are discussed.
A STUDY OF RADAR FEATURES OF WIND TURBINES IN THE HF BAND
2013-12-06
PIER
Vol. 143, 575-604, 2013
download: 243
Forward-Looking Imaging of Scanning Phased Array Radar Based on the Compressed Sensing
Xiaoyang Wen , Gangyao Kuang , Jiemin Hu , Ronghui Zhan and Jun Zhang
In this paper, a novel forward-looking imaging method based on the compressed sensing is proposed for scanning phased array radar (PAR) in order to improve the azimuth resolution,. Firstly, the echo of targets is modeled according to the principle of PAR. Then, it is analyzed why some of the former methods as multi-channel deconvolution are ineffective based on the signal model. Using a widely accepted assumption that dominant scatterers in an interesting area are sparse or compressible, an imaging algorithm based on the compressed sensing is proposed and investigated. This method obtains its high range resolution by transmitting and compressing chirp pulse signal, and improves its azimuth resolution by utilizing the compressed sensing technique. The effectiveness of the proposed method is illustrated and analyzed with simulations data.
FORWARD-LOOKING IMAGING OF SCANNING PHASED ARRAY RADAR BASED ON THE COMPRESSED SENSING
2013-12-06
PIER
Vol. 143, 559-574, 2013
download: 333
Comparative Modeling of Single-Ended through -Silicon Vias in GS and GSG Configurations Up to V-Band Frequencies
Kuan-Chung Lu and Tzyy-Sheng Horng
This work presents a novel comparative modeling scheme for single-ended (SE) through-silicon vias (TSVs) in GSG and GS configurations. Physical scalable models based on the equations developed herein indicate that the use of two symmetric ground TSVs in GSG configuration relatively increases the parasitic capacitance and conductance in the silicon substrate. However, this increase in the parasitic capacitance requires that the parasitic inductance of SE TSV is reduced to maintain the same phase velocity in silicon. According to the modeling results, the GSG configuration has a larger insertion loss than that of the GS configuration because the former has a higher substrate conductance. Nevertheless, when measured using RF coaxial probes, the GSG configuration exhibits a larger measurement bandwidth than the GS configuration. Finally, with the assistance of a double-sided probing system, wideband S-parameter measurement can validate the established equivalent-circuit model of SE TSV in GSG configuration up to V-band frequencies.
COMPARATIVE MODELING OF SINGLE-ENDED THROUGH-SILICON VIAS IN GS AND GSG CONFIGURATIONS UP TO V-BAND FREQUENCIES
2013-12-06
PIER
Vol. 143, 545-558, 2013
download: 234
Tunable Metamaterials Made of Graphene-Liquid Crystal Multilayers
Amir Madani , Shuomin Zhong , Habib Tajalli , Samad Roshan Entezar , Abdolrahman Namdar and Yungui Ma
The dispersion properties of an anisotropic metamaterial composed of periodic stacking of graphene-liquid crystal layers are investigated in the far-infrared region. It is represented that this structure is able to show both the elliptic and hyperbolic dispersions using the tunable properties of the graphene and liquid crystal. The switching between two dispersion phases via control of the temperature, voltage and external electric field is studied. It is shown that this switching can be used to control of the transmission and reflection at the interface of the metamaterial and air.
TUNABLE METAMATERIALS MADE OF GRAPHENE-LIQUID CRYSTAL MULTILAYERS
2013-12-02
PIER
Vol. 143, 519-544, 2013
download: 216
Coupling of Thresholding and Region Growing Algorithm for Change Detection in SAR Images
Bhogendra Mishra and Junichi Susaki
In this research paper, we propose supervised and unsupervised change detection methodologies focused on the analysis of multitemporal Synthetic Aperture Radar (SAR) images. These approaches are based on three main steps: (1) a comparison of multitemporal image was carried out by normalized difference ratio (NDR) operator; (2) implementing a novel supervised or unsupervised thresholding and (3) generating the change map by coupling of thresholding along with a region growing algorithm. In the first step, the two filtered multitemporal images were used to generate NDR image that was subjected to analysis. In the second step, by assuming a Gaussian distribution in the nochange area, we identified the pixel range that fits the Gaussian distribution better than any other range iteratively to detect the no-change area that eventually separates the change areas. In the supervised method, several sample no-change pixels were selected and the mean (μ) and the standard deviation (σ) were obtained. Then, μ±3σ was applied to select the best threshold values. Finally, a traditional thresholding algorithm was modified and implemented with the coupling of the region growing algorithm to consider the spatial information to generate the change map. The Gaussian distribution was assumed because it better fits the conditional densities of the no-change class in the NDR image. The effectiveness of the proposed methods was verified with the simulated images and the real images associated to geographical locations. The results were compared with the manual trial and error procedure (MTEP) and traditional unsupervised expectation-maximization (EM) method. Both proposed methods gave similar results with MTEP and significant improvement in Kappa coefficient in comparison to the traditional EM method was found in both cities. The coupling of the modified thresholding with the region growing algorithm is very effective with all methods.
COUPLING OF THRESHOLDING AND REGION GROWING ALGORITHM FOR CHANGE DETECTION IN SAR IMAGES
2013-12-01
PIER
Vol. 143, 503-518, 2013
download: 260
Analysis of a Double-Layered Vivaldi Antenna Inside a Metallic Enclosure
Majid OstadRahimi , Lotfollah Shafai and Joe LoVetri
A double-layered Vivaldi antenna enclosed by a metallic cylindrical cavity is investigated. The antenna is correlated to the same-size circular horn antenna to exploit the equivalent modal distribution of the Vivaldi-cavity antenna. It is shown that the TM11 and TE11 are the dominant modes and the proposed antenna operates similar to a dual-mode conical horn. The antenna is fabricated and successfully tested. The radiation characteristics, mutual coupling, as well as cross-polarization level are compared to a similarly sized Vivaldi without any metallic enclosure.
ANALYSIS OF A DOUBLE-LAYERED VIVALDI ANTENNA INSIDE A METALLIC ENCLOSURE
2013-11-29
PIER
Vol. 143, 485-501, 2013
download: 316
Theoretical Analysis of Resonant Wireless Power Transmission Links Composed of Electrically Small Loops
Alexandre Robichaud , Martin Boudreault and Dominic Deslandes
This paper presents an analytical method to calculate the scattering parameters of a wireless power transmission link composed of electrically small single loop resonators. The proposed method takes into account all the different couplings in the structure. First, the method is presented and used to find the S-parameters for links composed of circular and rectangular resonators. The model is then used to find the optimal topology for a given transmission distance. Validation of the model is done by comparing its results with experimental measurements. Based on this model, a software used for the design of wireless power transmission links has been developed and is presented. Finally, demonstrations that this model produces excellent results are provided. At resonant frequency, an accuracy better than 2% is reached.
THEORETICAL ANALYSIS OF RESONANT WIRELESS POWER TRANSMISSION LINKS COMPOSED OF ELECTRICALLY SMALL LOOPS
2013-11-21
PIER
Vol. 143, 447-461, 2013
download: 202
Spectral-Domain Formulation of Pillar-Type Photonic Crystal Waveguide Devices of Infinite Extent
Yoshimasa Nakatake and Koki Watanabe
This paper presents a novel formulation for the modeling of electromagnetic wave propagation in pillar-type photonic crystal waveguide devices. The structure under consideration is formed in an in nitely extended pillar-type photonic crystal and the wave propagation is controlled by removing some cylinders from the original periodic structure. The structure is considered as cascade connections of straight waveguides, and the input/output properties of the devices are obtained using an analysis method of multilayer structure. Each layer includes periodic circular cylinder array with defects, and the transfer-matrix is obtained by using a spectral-domain approach based on the recursive transition-matrix algorithm with the lattice sums technique and the pseudo-periodic Fourier transform.
SPECTRAL-DOMAIN FORMULATION OF PILLAR-TYPE PHOTONIC CRYSTAL WAVEGUIDE DEVICES OF INFINITE EXTENT
2013-11-20
PIER
Vol. 143, 421-445, 2013
download: 299
A Wideband Frequency-Shift Keying Modulation Technique Using Transient State of a Small Antenna (Invited Paper)
Mohsen Salehi , Majid Manteghi , Seong-Youp Suh , Soji Sajuyigbe and Harry G. Skinner
The rate of wireless data transmission is limited by the antenna bandwidth. We present an efficient technique to realize a high-rate direct binary FSK modulation by using the transient properties of high-Q antennas. We show that if the natural resonance of a narrowband resonant-type antenna is switched at a high rate, the radiating signal follows the variation of resonant frequency and provides a high-rate data-transmission regardless of the narrowband characteristics of the antenna. The bit-rate in this method is dictated by the switching speed rather than the impedance bandwidth. Since the proposed technique employs the antenna in a time-varying arrangement, carrier frequencies are not required to be simultaneously within the antenna bandwidth. When demanded, the antenna is tuned to required carrier frequency according to a sequence of digital data. Moreover, if the switching frequency is properly chosen such that the stored energy in the near-zone is not dramatically disturbed, any variation in the antenna resonance will instantaneously appear in the far-field radiation due to the previously accumulated energy in the near field. Therefore, depending on the Q factor and switching speed, radiation bandwidth of the antenna can be improved independently from the impedance bandwidth. Furthermore, we show that a single RF source is sufficient to excite both carrier frequencies and the need for a VCO is obviated. Experimental results are presented to validate the feasibility of the proposed technique.
A WIDEBAND FREQUENCY-SHIFT KEYING MODULATION TECHNIQUE USING TRANSIENT STATE OF A SMALL ANTENNA (Invited Paper)
2013-11-18
PIER
Vol. 143, 405-419, 2013
download: 336
Early Stage Breast Cancer Detection Using Indirect Microwave Holography
Michael Elsdon , Okan Yurduseven and David Smith
A novel microwave imaging approach for early stage breast cancer detection is described. The proposed technique involves the use of an Indirect Microwave Holographic technique employing a patented synthetic reference wave. This approach offers benefits in terms of simplicity, expense, comfort and safety when compared to current mammography techniques. Experimental results using a simulated breast phantom are included to demonstrate the validity of this technique to obtain 2D images. The technique is then extended to demonstrate the possibility of obtaining 3D images by using indirect stereoscopic holographic imaging.
EARLY STAGE BREAST CANCER DETECTION USING INDIRECT MICROWAVE HOLOGRAPHY
2013-11-18
PIER
Vol. 143, 385-404, 2013
download: 268
A New 2D Non-Spurious Discontinuous Galerkin Finite Element Time Domain (DG-FETD) Method for Maxwell's Equations
Qiang Ren , Luis E. Tobon and Qing Huo Liu
A new discontinuous Galerkin Finite Element Time Domain (DG-FETD) method for Maxwell's equations is developed. It can suppress spurious modes using basis functions based on polynomials with the same order of interpolation for electric field intensity and magnetic flux density (EB scheme). Compared to FETD based on EH scheme, which reqires different orders of interpolation polynomials for electric and magnetic field intensities, this method uses fewer unknowns and reduces the computation load. The discontinuous Galerkin method is employed to implement domain decomposition for the EB scheme based FETD. In addition, a well-posed time-domain perfectly matched layer (PLM) is extended to the EB scheme to simulate the unbounded problem. Leap frog method is utilized for explicit time stepping. Numerical results demonstrate that the above proposed methods are effective and efficient for 2D time domain TMz multi-domain problems.
A NEW 2D NON-SPURIOUS DISCONTINUOUS GALERKIN FINITE ELEMENT TIME DOMAIN (DG-FETD) METHOD FOR MAXWELL'S EQUATIONS
2013-11-13
PIER
Vol. 143, 369-384, 2013
download: 685
Low Losses Power Distribution Networks in Stripline Technology for Planar Array Antennas
Jose Manuel Inclan-Alonso , Jose-Manuel Fernandez Gonzalez and Manuel Sierra-Perez
Nowadays low profile passive array planar antennas are being more and more used substituting traditional parabolic antennas in satellite communications. To achieve a good efficiency in printed arrays it is necessary to use a low losses network. A shielded suspended stripline is proposed in this paper. The main aim of this network is to distribute the power among subarrays in an array antenna with minimum losses. Several vertical transitions to subarrays are shown besides some network designs for square arrays at X band.
LOW LOSSES POWER DISTRIBUTION NETWORKS IN STRIPLINE TECHNOLOGY FOR PLANAR ARRAY ANTENNAS
2013-11-08
PIER
Vol. 143, 349-368, 2013
download: 209
Enhanced Design of Narrowband Filters Based on the Extraordinary Transmission through Single Fishnet Structures
Nicholas S. Nye , Alexandros I. Dimitriadis , Nikolaos V. Kantartzis and Theodoros Tsiboukis
A systematic method for the efficient design of narrowband filters founded on the extraordinary transmission via single fishnet structures (SFSs) is presented in this paper.~Essentially, due to its strong resonant behavior, this phenomenon is proven suitable for the implementation of high-$Q$ devices.~The new design formulas are derived through the combination of full-wave numerical simulations and curve fitting algorithms. Also, adequate mathematical criteria are defined for the evaluation of the filters' linear performance, indicating that the transmitted electromagnetic waves remain practically undistorted in the frequency band of interest. Then, by exploiting the previously developed relations, proper correction factors are introduced in the existing SFS equivalent circuit expressions, which hardly increase the overall computational complexity. This quantitative modification leads to an enhanced characterization of SFSs, as key components for diverse applications. Finally, several limitations as well as possible ways of extending the featured algorithm to more complicated structures and higher frequency bands are briefly discussed.
ENHANCED DESIGN OF NARROWBAND FILTERS BASED ON THE EXTRAORDINARY TRANSMISSION THROUGH SINGLE FISHNET STRUCTURES
2013-11-08
PIER
Vol. 143, 331-347, 2013
download: 203
Time-Frequency and ISAR Characteristics of Wind Turbines with Higher Order Motions
Aale Naqvi and Hao Ling
Radar features from higher order motions of a wind turbine undergoing rotation are studied. Mathematical models for the motions are proposed and used to simulate the joint time-frequency (JTF) and inverse synthetic radar aperture (ISAR) characteristics of the motions. The motions are studied for an isolated turbine as well as for a turbine rotating above a ground. Selected motions are corroborated by laboratory model measurements.
TIME-FREQUENCY AND ISAR CHARACTERISTICS OF WIND TURBINES WITH HIGHER ORDER MOTIONS
2013-11-08
PIER
Vol. 143, 315-330, 2013
download: 324
Inductively Coupled Loop Antenna Design for UHF RFID on-Body Applications
Min-Chuan Tsai , Chien-Wen Chiu , Hwang-Cheng Wang and Ter-Feng Wu
This paper presents a one-wavelength loop antenna fed by an inductively coupled loop for on-body applications. An equivalent circuit for the inductively coupled loop antenna is proposed to synthesize the antenna system with a microchip. The designed tag is printed on a PVC substrate and placed close to a four-layer stratified elliptical cylinder human model. The card-type tag measures 85.5 × 54 × 0.76 mm3 and is suitable for use on a student ID card for a broad range of applications. The impedance bandwidth of the inductively coupled loop tag antenna is 60 MHz (880-940 MHz, 6.6%), which covers the operating UHF bands in U.S. and Taiwan. The measured reading distance ranges from 2.7 to 5.7 meters when placed at different positions on the chest of a human body in the open site.
INDUCTIVELY COUPLED LOOP ANTENNA DESIGN FOR UHF RFID ON-BODY APPLICATIONS
2013-11-08
PIER
Vol. 143, 285-314, 2013
download: 196
Dispersion and Local-Error Analysis of Compact Lfe-27 Formula for Obtaining Sixth-Order Accurate Numerical Solutions of 3D Helmholtz Equation
Sin-Yuan Mu and Hung-Wen Chang
We present the dispersion and local-error analysis of the twenty-seven point local field expansion (LFE-27) formula for obtaining highly accurate semi-analytical solutions of the Helmholtz equation in a 3D homogeneous medium. Compact finite-difference (FD) stencils are the cornerstones in frequency-domain FD methods. They produce block tri-diagonal matrices which require much less computing resources compared to other non-compact stencils. LFE-27 is a 3D compact FD-like stencil used in the method of connected local fields (CLF) [1]. In this paper, we show that LFE-27 possesses such good numerical quality that it is accurate to the sixth order. Our analyses are based on the relative error studies of numerical phase and group velocities. The classical second-order FD formula requires more than twenty sampling points per wavelength to achieve less than 1% relative error in both phase and group velocities, whereas LFE-27 needs only three points per wavelength to match the same performance.
DISPERSION AND LOCAL-ERROR ANALYSIS OF COMPACT LFE-27 FORMULA FOR OBTAINING SIXTH-ORDER ACCURATE NUMERICAL SOLUTIONS OF 3D HELMHOLTZ EQUATION
2013-11-04
PIER
Vol. 143, 263-284, 2013
download: 179
A Dressed-State Assisted Left-Handed Coherent Medium for High-Gain Optical Amplification
Katus Maski
A scheme of double-negative left-handed atomic vapor medium based on dressed-state assisted simultaneous electric and magnetic resonances is suggested. In this mechanism, simultaneous electric- and magnetic-dipole allowed transitions of atoms are driven by an optical wave by taking full advantage of both mixed-parity dressed-state assisted resonance and incoherent population pumping in a quantum-coherent atomic medium (e.g., alkali-metal atomic vapor). Since the simultaneously negative permittivity and permeability can be achieved in a same frequency band, such an atomic vapor will exhibit an incoherent-gain double-negative refractive index that is three-dimensionally isotropic and homogeneous. The imaginary part of the negative refractive index of the present atomic vapor would be drastically suppressed or would become negative because of loss compensation through incoherent population transfer. The quantumcoherent left-handed atomic vapor presented here will have four characteristics: i) three-dimensionally isotropic and homogeneous negative refractive index, ii) double-negative atomic medium at visible (and infrared) wavelengths, iii) tunable negative refractive index based on dressed-state quantum coherence, and iv) high gain due to incoherent pumping action.
A DRESSED-STATE ASSISTED LEFT-HANDED COHERENT MEDIUM FOR HIGH-GAIN OPTICAL AMPLIFICATION
2013-11-01
PIER
Vol. 143, 243-261, 2013
download: 281
Dual-Band Circular Polarizer and Asymmetric Spectrum Filter Using Ultrathin Compact Chiral Metamaterial
He-Xiu Xu , Guang-Ming Wang , Mei-Qing Qi and Tong Cai
A compact chiral metamaterial is proposed and comprehensively investigated that can achieve circularly polarized wave emission from linearly polarized incident wave (giant circular dichroism) over dual bands and near Diodelike asymmetric transmission of linearly polarized waves. The chiral metamaterial also features exceptionally strong optical activity. For verification, two proof-of-concept slab samples are designed, fabricated and measured at microwave frequencies. Numerical and experimental results agree well, indicating that the former dual-band circular polarizer features high conversion efficiency around 8.1 and 9.9 GHz in addition to large polarization extinction ratio of more than 16 dB, while the latter chiral sample enables the near 90% cross-polarization transmission in one direction and almost 10% transmission in the opposite direction. The block "meta-atom" that utilized to build the ultrathin CMM slab is less than λ0/6.73 evaluated at operating frequency. Good performances of the two chiral slabs with simple and compact package suggest promising applications in the circular polarizers (circulators) and transparent linear polarization transformers or spectrum filters (isolators) that need to be interpreted with other compact devices.
DUAL-BAND CIRCULAR POLARIZER AND ASYMMETRIC SPECTRUM FILTER USING ULTRATHIN COMPACT CHIRAL METAMATERIAL
2013-11-01
PIER
Vol. 143, 223-242, 2013
download: 205
Parallel Implementation and Application of the MRTD with an Efficient Cfs-PML
Yawen Liu , Yi-Wang Chen and Pin Zhang
In this paper, we describe two parallel MRTD algorithms. Both algorithms are proved to be feasible by comparing the result of the serial MRTD method, the efficiency of them are also compared in order to evaluate a better strategy. Moreover, a novel implementation of "complex frequency-shifted" perfect matched layer (CFS-PML) with auxiliary differential equation (ADE) is presented for the MRTD method. The implementation is easier to obtain and more memory saving when treating more generalized media, and numerical results demonstrate that the CFS-PML with ADE is more absorptive than the popularly used APML. Furthermore, using one of the parallel algorithms and the CFS-PML, the characteristic of the field cross-section distribution of the electromagnetic pulse (EMP) propagation in vaulted tunnel is studied.
PARALLEL IMPLEMENTATION AND APPLICATION OF THE MRTD WITH AN EFFICIENT CFS-PML
2013-11-01
PIER
Vol. 143, 207-221, 2013
download: 224
Single-Feed Triple-Band Circularly Polarized Spidron Fractal Slot Antenna
Thuy Nguyen Thi , Son Trinh-Van , Gina Kwon and Keum Cheol Hwang
In this paper, the design of a single-feed triple-band circularly polarized Spidron fractal slot antenna is presented. The proposed antenna is composed of a Spidron fractal slot, a Z-shaped slit, and two L-shaped slits to realize triple-band circular polarization operation. A simple 50 Ω microstrip line is utilized to feed the proposed antenna. A conducting reflector is also used to reduce back radiation, thereby enhancing the forward antenna gain. The proposed antenna has total dimensions of 40.7 mm × 40.7 mm × 18.52 mm (0.42λ × 0.42λ × 0.19λ) and was fabricated and tested. The experimental results show that the proposed antenna has -10 dB reflection coefficient bandwidths from 2.76 GHz to 3.13 GHz and from 3.56 GHz to 6.22 GHz. The measured 3 dB axial ratio bandwidths are 2.28% (3.04-3.11 GHz) for the lower band, 7.15% (4.18-4.49 GHz) for the middle band, and 2.6% (4.93-5.06 GHz) for the upper band. The peak gains within the -10 dB reflection coefficient bandwidths are 3.41 dBic and 6.29 dBic, respectively.
SINGLE-FEED TRIPLE-BAND CIRCULARLY POLARIZED SPIDRON FRACTAL SLOT ANTENNA
2013-10-31
PIER
Vol. 143, 187-206, 2013
download: 267
Radiometric Method for Emissivity Retrieval in High Reflective Materials
Marco Canavero and Axel Murk
High reflective materials in the microwave region play a very important role in the realization of antenna reflectors for a broad range of applications, including radiometry. These reflectors have a characteristic emissivity which needs to be characterized accurately in order to perform a correct radiometric calibration of the instrument. Such a characterization can be performed by using open resonators, waveguide cavities or by radiometric measurements. The latter consists of comparative radiometric observations of absorbers, reference mirrors and the sample under test, or using the cold sky radiation as a direct reference source. While the first two mentioned techniques are suitable for the characterization of metal plates and mirrors, the latter has the advantages to be also applicable to soft materials. This paper describes how, through this radiometric techniques, it is possible to characterize the emissivity of the sample relative to a reference mirror and how to characterize the absolute emissivity of the latter by performing measurements at different incident angles. The results presented in this paper are based on our investigations on emissivity of a multilayer insulation material (MLI) for space mission, at the frequencies of 22 and 90 GHz.
RADIOMETRIC METHOD FOR EMISSIVITY RETRIEVAL IN HIGH REFLECTIVE MATERIALS
2013-10-29
PIER
Vol. 143, 165-185, 2013
download: 212
Azimuth Nonlinear Chirp Scaling Integrated with Range Chirp Scaling Algorithm for Highly Squinted SAR Imaging
Qinglin Zhai , Wei Wang , Jiemin Hu and Jun Zhang
The difficulty of focusing high-resolution highly squinted SAR data comes from the serious azimuth-range coupling, which needs to be compensated in the procedure of imaging. Generally, the linear range walk correction (LRWC) can reduce the coupling effectively, however, it also induces the problem of azimuth-dependence of residual range cell migration (RCM) and quadratic phase. A novel algorithm is proposed to solve this problem in this paper. In this algorithm, the azimuth nonlinear chirp scaling (ANCS) operation is used, which can not only eliminate the azimuth space variation of residual RCM and frequency modulation (FM) rate but also remove the azimuth misregistration. In addition, the range chirp scaling operation is applied to correct the range-dependent RCM. After implementing the unified RCM correction, range compression and azimuth compression sequentially, the focused SAR image is acquired finally. The experimental results with simulated data demonstrate that the proposed algorithm outperforms the existing algorithms.
AZIMUTH NONLINEAR CHIRP SCALING INTEGRATED WITH RANGE CHIRP SCALING ALGORITHM FOR HIGHLY SQUINTED SAR IMAGING
2013-10-29
PIER
Vol. 143, 143-163, 2013
download: 234
Propagation of a Lorentz-Gauss Vortex Beam in a Turbulent Atmosphere
Guoquan Zhou and Guoyun Ru
The propagation properties of a Lorentz-Gauss vortex beam in a turbulent atmosphere are investigated. Based on the extended Huygens-Fresnel integral, the Hermite-Gaussian expansion of a Lorentz function, etc., analytical expressions of the average intensity, effective beam size, and kurtosis parameter of a Lorentz-Gauss vortex beam are derived in the turbulent atmosphere. The spreading properties of a Lorentz-Gauss vortex beam in the turbulent atmosphere are numerically calculated and analyzed. The influences of the beam parameters on the propagation of a Lorentz-Gauss vortex beam in the turbulent atmosphere are examined in details. Upon propagation in the turbulent atmosphere, the vale in the normalized intensity distribution of a Lorentz-Gauss vortex beam gradually rises. The rising speed of the vale is opposite to the spreading of the beam spot. When the propagation distance reaches to a certain value, the Lorentz-Gauss vortex beam in the turbulent atmosphere becomes a flattened beam spot. When the propagation distance is large enough, the beam spot of the Lorentz-Gauss vortex beam tends to be a Gaussian-like distribution. This research is beneficial to optical communications and remote sensing that are involved in the single mode diode laser devices.
PROPAGATION OF A LORENTZ-GAUSS VORTEX BEAM IN A TURBULENT ATMOSPHERE
2013-10-29
PIER
Vol. 143, 131-141, 2013
download: 211
Three-Dimensional Thermal Cloak with Homogeneous and Nonsingular Conductive Materials
Tiancheng Han and Zheng-Mao Wu
Most three-dimensional omnidirectional cloaks proposed to date (using optics, electromagnetics, and acoustics) are not easily realized, as they possess inhomogeneous and singular parameters imposed by the transformation-optic method. In this study, we theoretically demonstrate that a thermodynamic spherical cloak with homogeneous and finite conductivity and employing only naturally available conductive materials may be achieved. More interestingly, the thermal localization inside the coating layer can be tuned by anisotropy, which may lead to nearly perfect functionality in an incomplete cloak. The practical realization of such a homogeneous thermal cloak by using two naturally occurring materials has been suggested, which provides an unprecedentedly plausible way to flexibly achieve a thermal cloak and manipulate heat flow. Numerical experiments validate the excellent performance of the proposed homogeneous cloak functions.
THREE-DIMENSIONAL THERMAL CLOAK WITH HOMOGENEOUS AND NONSINGULAR CONDUCTIVE MATERIALS
2013-10-28
PIER
Vol. 143, 105-130, 2013
download: 256
A Systematic Design Procedure for Microstrip-Based Unidirectional UWB Antennas
Purna B. Samal , Ping Jack Soh and Guy Vandenbosch
A design procedure for microstrip antenna topologies operating within the full UWB band is described. The presence of the full ground plane successfully results in a unidirectional antenna, which is important in applications related to Wireless Body Area Networks (WBAN). The existing broadbanding concepts have been creatively combined throughout the design to enable the UWB behavior, while simultaneously keeping the full ground plane intact. The procedure is validated with a concrete design of a microstrip type UWB antenna operating from 3.6 GHz to 10.3 GHz.
A SYSTEMATIC DESIGN PROCEDURE FOR MICROSTRIP-BASED UNIDIRECTIONAL UWB ANTENNAS
2013-10-28
PIER
Vol. 143, 87-104, 2013
download: 283
Micro-Doppler Analysis of Korean Offshore Wind Turbine on the L-Band Radar
Joo-Ho Jung , Un Lee , Si-Ho Kim and Sang-Hong Park
To cope with the energy shortage and the rising cost of the fossil fuel, many wind farms are being constructed under the supervision of Korean government along the coasts of Korean peninsula to generate clean and renewable energy. However, construction of these wind farms may cause negative effect on various L-band radars in operation. This paper presents the result of the micro-Doppler (MD) analysis of the influence of the wind turbine on the L-band radar using the point scatterer model and the radar cross section of the real turbine predicted by the method of physical optics. The simulation results obtained at three observation angles show that the range of MD occupies a considerable portion of the helicopter MD range, and thus, the operations using helicopters need to be avoided in the wind farm region, and additional radars are required for the recognition of helicopter-like objects.
MICRO-DOPPLER ANALYSIS OF KOREAN OFFSHORE WIND TURBINE ON THE L-BAND RADAR
2013-10-28
PIER
Vol. 143, 67-86, 2013
download: 301
Compact Electromagnetic Absorbers for Frequencies Below 1 GHz
Rodolfo Araneo , Giampiero Lovat and Salvatore Celozzi
A novel Frequency Selective Surface (FSS) configuration is proposed for the design of polarization-insensitive metamaterial absorbers operating below 1 GHz, where the first resonances of small commercial enclosures appear. The novel FSS shows a strong subwavelength response, enhanced by the dielectric substrate, which allows the design of compact planar absorbers with excellent angular and polarization stability.
COMPACT ELECTROMAGNETIC ABSORBERS FOR FREQUENCIES BELOW 1 GHZ
2013-10-25
PIER
Vol. 143, 47-66, 2013
download: 261
Generalized Wait-Hill Formulation Analysis of Lumpedelement Periodically-Loaded Orthogonal Wire Grid Generic Frequency Selective Surfaces
Christos Mias and Angelo Freni
By combining the work of J.R. Wait on a periodically loaded vertical wire grid and the work of D.A. Hill and J.R. Wait on a wire mesh, a novel generalized formulation, the Wait-Hill formulation, is obtained for the analysis of lumped-element periodically-loaded orthogonal wire grid generic frequency selective surfaces. The Wait-Hill formulation is simple and not restricted by the miniaturization assumption of current approximate simple methods for the analysis of loaded and unloaded wire grids. The results of the Wait-Hill formulation are shown to agree well with those of a commercial software.
GENERALIZED WAIT-HILL FORMULATION ANALYSIS OF LUMPEDELEMENT PERIODICALLY-LOADED ORTHOGONAL WIRE GRID GENERIC FREQUENCY SELECTIVE SURFACES
2013-10-21
PIER
Vol. 143, 19-46, 2013
download: 272
A Refined Two-Dimensional Nonlinear Chirp Scaling Algorithm for Geosynchronous Earth Orbit SAR
Tao Zeng , Wenfu Yang , Zegang Ding , Dacheng Liu and Teng Long
Taking into account long signal propagation time, curved orbit and ``near-far-near'' slant range histories at apogee, a refined slant range model (RSRM) is presented for geosynchronous earth orbit synthetic aperture radar (GEO SAR) in this paper. Additional linear component and high order components are introduced into straight orbit assumption (SOA) model to describe relative motion during long signal propagation and curved orbit respectively. And the special slant range histories at apogee are considered through adding terms changing with the sign of Doppler rate. Then, based on RSRM under an ideal acquisition and ignoring nonideal factors (such as depolarization and attenuation effects), a refined two-dimensional nonlinear chirp scaling algorithm (RTNCSA) is proposed. Space-variant range cell migration (RCM) caused by range-variant effective velocities is corrected by refined range nonlinear chirp scaling algorithm, and the variable Doppler parameters in azimuth direction are equalized through refined azimuth nonlinear chirp scaling algorithm. Finally, RSRM is verified by 600-second direct signal received by a stationary receiver on a tall building from BeiDou navigation satellite, and RTNCSA is validated through simulated point array targets with resolution of 5 m and scene size of 150 km.
A REFINED TWO-DIMENSIONAL NONLINEAR CHIRP SCALING ALGORITHM FOR GEOSYNCHRONOUS EARTH ORBIT SAR
2013-10-18
PIER
Vol. 143, 1-18, 2013
download: 266
Modeling and Layout Optimization Techniques for Silicon-Based Symmetrical Spiral Inductors
Choon Beng Sia , Wei Meng Lim , Beng Hwee Ong , Ah Fatt Tong and Kiat Seng Yeo
A scalable and highly accurate RF symmetrical inductor model (with model error of less than 5%) has been developed from more than 100 test structures, enabling device performance versus layout size trade-offs and optimization up to 10 GHz. Large conductor width designs are found to yield good performance for inductors with small inductance values. However, as inductance or frequency increases, interactions between metallization resistive and substrate losses render the use of large widths unfavorable as they consume silicon area and degrade device performance. These findings are particularly important when exploiting the cost-effective silicon-based RF technologies for applications with operating frequencies greater than 2.5 GHz.
MODELING AND LAYOUT OPTIMIZATION TECHNIQUES FOR SILICON-BASED SYMMETRICAL SPIRAL INDUCTORS