Vol. 134
Latest Volume
All Volumes
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]
2012-12-07
PIER
Vol. 134, 559-579, 2013
download: 122
Split-Field Finite-Difference Time-Domain Scheme for Kerr-Type Nonlinear Periodic Media
Jorge Frances Monllor Jani Tervo Cristian Neipp
The Split-Field Finite-Difference Time-Domain (SFFDTD) formulation is extended to periodic structures with Kerr-type nonlinearity. The optical Kerr effect is introduced by an iterative fixed-point procedure for solving the nonlinear system of equations. Using the method, formation of solitons inside homogenous nonlinear media is numerically observed. Furthermore, the performance of the approach with more complex photonic systems, such as high-reflectance coatings and binary phase gratings with high nonlinearity is investigated. The static and the dynamic behavior of the Kerr effect is studied and compared to previous works.
SPLIT-FIELD FINITE-DIFFERENCE TIME-DOMAIN SCHEME FOR KERR-TYPE NONLINEAR PERIODIC MEDIA
2012-12-07
PIER
Vol. 134, 543-558, 2013
download: 111
Block Matrix Preconditioner Method for the Electric Field Integral Equation (EFIE) Formulation Based on Loop-Star Basis Functions
Jae-Hyun Yeom Huicheol Chin Hyo-Tae Kim Kyung-Tae Kim
In this paper, electromagnetic scattering problems are analyzed using an electric field integral equation (EFIE) formulation that is based on loop-star basis functions so as to avoid low-frequency instability problems. Moreover, to improve the convergence rate of iterative methods, a block matrix preconditioner (BMP) is applied to the EFIE formulation which is based on loop star-basis functions. Because the matrix system resulting from the conventional method of moments is a dense matrix, a sparse matrix version of each block matrix is constructed, followed by the inversion of the resultant block sparse matrix using incomplete factorization. Numerical results show that the proposed BMP is efficient in terms of computation time and memory usage.
BLOCK MATRIX PRECONDITIONER METHOD FOR THE ELECTRIC FIELD INTEGRAL EQUATION (EFIE) FORMULATION BASED ON LOOP-STAR BASIS FUNCTIONS
2012-12-06
PIER
Vol. 134, 509-524, 2013
download: 139
Luminescence Enhancement of Oled Performance by Doping Colloidal Magnetic FE3O4 Nanoparticles
Mahmut Kus Faruk Ozel Nurhan Mehmet Varal Mustafa Ersoz
We report synthesis of magnetic Fe3O4 nanoparticles (MNPs) based on two phase method and their application in organic light-emitting devices (OLEDs) as blend with emissive Polyfluorene (PFO) matrix. Two phase method allows to successively synthesizing oleic acid capped MPNs with 5-10 nm particle size. Colloidal MNPs can be easily mixed with emissive polymer solutions to obtain a blend for OLED application. The electroluminescence efficiency increases by doping with MNPs into emissive layer. Different dopant concentrations varied from 0.4% to 2% were monitored. It was observed that the electroluminescence increases up to 1% v/v doping ratio. The luminance of OLEDs increased from 15.000 cd/m² to 24.000 cd/m² in comparison pristine device with 1% MNP doped device.
LUMINESCENCE ENHANCEMENT OF OLED PERFORMANCE BY DOPING COLLOIDAL MAGNETIC FE<sub>3</sub>O<sub>4</sub> NANOPARTICLES
2012-12-06
PIER
Vol. 134, 475-507, 2013
download: 125
Finite Data Performance Analysis of MVDR Antenna Array Beamformers with Diagonal Loading
Yen Lin Chen Ju-Hong Lee
Diagonal loading has been regarded as an efficient manner to tackle the finite sample effect or the steering vector imprecision problem on adaptive array beamforming. However, the reason of the robustness improvement by the loading factor is still unknown and rarely discussed. In this paper, we consider the finite sample effect and derive the approximated output signal-to-interference-plus-noise ratio (SINR) of minimum variance distortionless response (MVDR) beamformers with diagonal loading. The obtained SINR expression is more explicit and compact than the existing formulas in the literature. Based on the theoretical results, we investigate the effects of a loading factor on the output SINR of MVDR beamformers. The theoretical analysis shows the effectiveness of diagonal loading on alleviating finite sample effect. Moreover, the price of using diagonal loading is also discussed. Simulation results are presented for confirming the validity of the research work.
FINITE DATA PERFORMANCE ANALYSIS OF MVDR ANTENNA ARRAY BEAMFORMERS WITH DIAGONAL LOADING
2012-12-06
PIER
Vol. 134, 455-474, 2013
download: 148
Multi-Feature Based Detection of Landmines Using Ground Penetrating Radar
Kyungmi Park Suncheol Park Kangwook Kim Kwang Hee Ko
In this paper, we present a method for detecting anti-tank or anti-personnel landmines buried in the ground. A set of data generated by a ground penetrating radar is processed to remove the surface reflection and clutter, yielding signals for possible landmines. In order to detect landmines in the signals, features are computed and compared against a database, which contains those of various landmines. Three features are proposed to use; principal components from principal component analysis, Fourier coefficients and singular values from singular value decomposition method, each of which is chosen to represent each landmine uniquely. Detection is performed using Mahalanobis distance-based method. Examples show that the proposed method can effectively detect landmines in various burial condition.
MULTI-FEATURE BASED DETECTION OF LANDMINES USING GROUND PENETRATING RADAR
2012-12-06
PIER
Vol. 134, 437-454, 2013
download: 198
High Performance Multi-Section Corrugated Slot-Coupled Directional Couplers
Alvaro Moscoso-Martir Inigo Molina-Fernandez Alejandro Ortega-Monux
In this paper a robust technique for the design of high performance directional couplers is proposed. It combines the advantages of wiggly coupled lines and slot-coupled lines but overcomes their main limitations. The key to this novel technique is a new corrugated slot that allows perfect compensation of the even and odd mode phase velocities and can be easily designed using Bloch-Floquet theory, yielding outstanding performance. To demonstrate the validity of the proposed technique, the design of two different wideband directional couplers is presented. The first design consists of a 10 dB asymmetric directional coupler with a one decade bandwidth (1.2-12 GHz) that exhibits a coupling accuracy of 10±0.6 dB, a return loss better than 23 dB and an isolation better than 28 dB across the complete frequency band. The second design consists of a symmetric quadature hybrid that operates over the complete UWB band (3.1 to 10.6 GHz) showing an amplitude and phase imbalance between the output ports lower than ±0.5 dB and ±0.7°, respectively.
HIGH PERFORMANCE MULTI-SECTION CORRUGATED SLOT-COUPLED DIRECTIONAL COUPLERS
2012-12-06
PIER
Vol. 134, 419-435, 2013
download: 144
An Iterative Source Reconstruction Method Exploiting Phaseless Electric Field Data
Ping Li Li Jun Jiang
Conventional equivalent source reconstruction methods (SRM) require both phase and amplitude information of the acquired field data. However, there are situations where the phase information is not available or impractical to obtain. Hence, the development of SRM using phaseless fields is important. In this paper, a novel iterative SRM based on phaseless electric fields is presented. The reconstructed equivalent current source can be electric, magnetic current, or both. They can fit the physical geometry of the radiator. Electric field integral equation (EFIE) is employed to build the relationship between the reconstructed current source and measured fields. It can precisely reproduce the original 3D radiation pattern with very good accuracy. To investigate the robustness and accuracy of the proposed approach, both strong and weakly-directional radiators are benchmarked.
AN ITERATIVE SOURCE RECONSTRUCTION METHOD EXPLOITING PHASELESS ELECTRIC FIELD DATA
2012-12-05
PIER
Vol. 134, 397-417, 2013
download: 134
A Novel Miniaturized Dual-Band Bandstop Filter Using Dual-Plane Defected Structures
Jun Wang Huansheng Ning Qingxu Xiong Minquan Li Ling-Feng Mao
A novel miniaturized dual-band bandstop filter (DBBSF) is proposed by using the T-shaped defected microstrip structures (DMSs) and the U-shaped defected ground structures (DGSs) in this paper. The layout of the dual-band bandstop resonator (DBBSR) is presented at first. The dual stopbands of the DBBSR can be separately controlled since the mutual coupling of the defected structures is negligible. The working principles of the T-shaped DMS and U-shaped DGS are then provided and their design process is summarized. On the basis of the DBBSR, the design methodology of the compact DBBSF is proposed before its design procedures are presented. Following the design procedures, a second-order and third-order DBBSFs with Butterworth frequency response are designed, simulated and fabricated. The equivalent circuit models of the designed filters are also developed. Full-wave simulation results of the fabricated DBBSFs are in good agreement with the circuit simulation and measurement results, validating our proposed design methodology.
A NOVEL MINIATURIZED DUAL-BAND BANDSTOP FILTER USING DUAL-PLANE DEFECTED STRUCTURES
2012-12-03
PIER
Vol. 134, 379-395, 2013
download: 169
Investigations of Four-Port Circulator Utilizing Cylindrical Ferrite Coupled Line Junction
Adam Kusiek Wojciech Marynowski Jerzy Mazur
In this paper the numerical and experimental investigations of four-port circulator utilizing longitudinally magnetized cylindrical ferrite coupled lines (CFCL) section are presented for the first time. In comparison to earlier models the proposed structure of circulator utilizes multilayer magic-T junction cascaded with cylindrical ferrite section of π/4 Faraday angle. The advantage of utilization of cylindrical section over the planar one is the possibility to design shorter ferrite junctions ensuring lower insertion losses. Moreover, the multilayer magic T-junction allows to improve performance of the proposed circulator by omitting the bandwidth limitation which exists in commonly used hybrid couplers with air-bridges. In the analysis of CFCL junction the full wave hybrid approach combining finite difference frequency domain method with method of moments and mode matching technique is applied. The planar feeding structures of circulator are designed with the use of commercial software. The simulated results of the entire circulator are compared with the measurement results of the fabricated prototype and a good agreement is achieved.
INVESTIGATIONS OF FOUR-PORT CIRCULATOR UTILIZING CYLINDRICAL FERRITE COUPLED LINE JUNCTION
2012-12-03
PIER
Vol. 134, 359-378, 2013
download: 158
Systematic Analysis of Conducted Electromagnetic Interferences for the Electric Drive System in Electric Vehicles
Yanjie Guo Lifang Wang Chenglin Liao
There are serious electromagnetic compatibility (EMC) problems in electric vehicles. In order to explain and solve them, a systematic method to analyze conducted interferences of the electric drive system is shown in this paper. This method represents the effects of the power battery which is the most different part between electric drive systems used in electric vehicles and other cases. Also, Equivalent models are established from power electronics devices to the entire system by considering both the working mechanism and stray parameters. Firstly, insulated gate bipolar transistor (IGBT) and inverter are studied as the main interference source. A new expression is put forward to estimate the frequency domain features of the inverter disturbances. Then, power battery and electric motor are discussed as the main propagation paths. Their high frequency circuit models are given with parameters obtained from tests and measurements. Finally, the system model is established. The system interferences are analyzed to get their generation causes, influence factors and frequency domain characteristics. Comparisons between simulations and experiments verify the correctness of the models and the method.
SYSTEMATIC ANALYSIS OF CONDUCTED ELECTROMAGNETIC INTERFERENCES FOR THE ELECTRIC DRIVE SYSTEM IN ELECTRIC VEHICLES
2012-12-01
PIER
Vol. 134, 337-357, 2013
download: 153
Theory of Zero-Power RFID Sensors Based on Harmonic Generation and Orthogonally Polarized Antennas
Federico Alimenti Luca Roselli
In this paper a novel approach is proposed to solve the issue of the absolute accuracy required by the most of passive chip-less RFID sensors. To this purpose the sensor information is encoded as the phase difference between two signals, one of the two acting as the reference signal for the other one. First the tag receives a carrier at frequency f0, then two equal signals at frequency 2 f0 are generated by means of a diode-based frequency doubler and a power divider. At this point one of the two signals is phase-shifted using a passive sensing element. Finally the 2 f0 signals are re-irradiated by exploiting two orthogonally polarized antennas. With this approach the sensor information can be extracted by a suitable reader equipped with two complex (I/Q) receivers. The idea will be first developed from a theoretical basis and then verified with several particular cases. The novel tag concept is compatible with paper substrate and ink-jet printing technology since antennas diodes and passive sensing elements, i.e. all the main tag components, are going to be developed on paper materials.
THEORY OF ZERO-POWER RFID SENSORS BASED ON HARMONIC GENERATION AND ORTHOGONALLY POLARIZED ANTENNAS
2012-11-29
PIER
Vol. 134, 323-336, 2013
download: 149
System Development of Microwave Induced Thermo-Acoustic Tomography and Experiments on Breast Tumor
Zhiqin Zhao Jian Song Xiaozhang Zhu Jinguo Wang Jiangniu Wu Yulang Liu Zai-Ping Nie Qing Huo Liu
Microwave induced thermo-acoustic tomography (MITAT) has become a keen research topic in recent years due to its great potential in early breast cancer detection. A secure and accurate MITAT system has been established. Some experiments have been made to demonstrate the performance of the MITAT system. Based on an experiment using phantom, some quantitative features of the system have been obtained. Some imaging experiments with real human breast cancer tissues are performed to demonstrate its effectiveness and the potential in clinical diagnosis. Images with both high contrast and fine spatial resolution are achieved by using time reversal mirror (TRM) technique in the imaging processing. Moreover, comparisons between the MITAT system result and an ultrasound imaging system result are made. From the comparison, the MITAT system shows its advantages of better contrast over the ultrasound imaging system. The system and the experiments in this paper verify the mechanism of MITAT for breast cancer detection and provide a prototype basis for clinical practice.
SYSTEM DEVELOPMENT OF MICROWAVE INDUCED THERMO-ACOUSTIC TOMOGRAPHY AND EXPERIMENTS ON BREAST TUMOR
2012-11-27
PIER
Vol. 134, 301-322, 2013
download: 110
Foreign Object Detection Based on Circular Bistatic Synthetic Aperture Radar
Mojtaba Mohammadpoor Raja Syamsul Azmir Raja Abdullah Alyani Ismail Ahmad Fauzi Abas
Synthetic Aperture Radar is well known for producing a radar image of the ground, so it can be used for detecting on-the-ground object which is interesting for some applications. A possible application can be Foreign Object Detection (FOD), which is an important issue in aviation safety. A ground-based Circular Bistatic Synthetic Aperture Radar (Circular-BiSAR) is introduced in this paper. The circular movement makes it more practical while the bistatic configuration offers some advantages. Wideband Linear Frequency Modulated (LFM) chirp pulses are employed here, for transmission and reception of reflection pulses to and from the under test object. A simulated model is developed for the system which analyzes the transmitting, receiving, Doppler and LFM signals by considering the distances and movement of antennas. A prototype system is launched, and some experiments are done to detect and localize various objects based on their reflection properties of microwaves. A processing algorithm is proposed in this paper to confirm the detection. The results show that the proposed system can detect and localize on-the ground objects with as small a dimension as 2 cm height and 2 cm diameter located several metres away.
FOREIGN OBJECT DETECTION BASED ON CIRCULAR BISTATIC SYNTHETIC APERTURE RADAR
2012-11-26
PIER
Vol. 134, 289-299, 2013
download: 115
A Wideband and Dual-Resonant Terahertz Metamaterial Using a Modified SRR Structure
Wanyi Guo Lianxing He Biao Li Teng Teng Xiao-Wei Sun
We present the design, fabrication and measurment of a dual-resonant broadband terahertz (THz) matamterial based on a modified split-ring resonator (MSRR) structure. The proposed MSRR is constructed by connecting the inner split ring with the outer split ring of adjacent cell. Transmission and reflection characteristics of the proposed structure are simulated using Ansoft HFSS, and the permittivities show negative values in 0.492-0.693 THz and 0.727-0.811 THz bands. The designed sample is fabricated on a gallium arsenide layer, and experiments are performed in Terahertz Time-Domain Spectroscopy. Measured transmission characteristics agree well with the simulations.
A WIDEBAND AND DUAL-RESONANT TERAHERTZ METAMATERIAL USING A MODIFIED SRR STRUCTURE
2012-11-25
PIER
Vol. 134, 267-288, 2013
download: 147
Target Recognition for Multi-Aspect SAR Images with Fusion Strategies
Ruo-Hong Huan Yun Pan
Two fusion strategies for target recognition using multi-aspect synthetic aperture radar (SAR) images are presented for recognizing ground vehicles in MSTAR database. Due to radar cross-section variability, the ability to discriminate between targets varies greatly with target aspect. Multi-aspect images of a given target are used to support recognition. In this paper, two fusion strategies for target recognition using multi-aspect SAR images are proposed, which are data fusion strategy and decision fusion strategy. The recognition performance sensitivity to the number of images and the aspect separations is analyzed for those two target recognition strategies. The two strategies are also compared with each other in probability of correct classification and operating efficiency. The experimental results indicate that if we have a small number of multi-aspect images of a target and the aspect separations between those images are proper, the probability of correct classification obtained by the two proposed strategies can be advanced significantly compared with that obtained by the method using single image.
TARGET RECOGNITION FOR MULTI-ASPECT SAR IMAGES WITH FUSION STRATEGIES
2012-11-24
PIER
Vol. 134, 247-266, 2013
download: 206
Isolation Improvement in a Dual-Band Dual-Element MIMO Antenna System Using Capacitively Loaded Loops
Mohammad S. Sharawi Ahmed B. Numan Daniel N. Aloi
A dual-band dual-element multiple-input-multiple-output (MIMO) antenna system with enhanced isolation is proposed. The MIMO antenna system is based on printed 4-shaped antenna elements. Dual band isolation is achieved by using an array of printed capacitively loaded loops (CLLs) on the top side of the board for high band isolation improvement and a complementary CLL structure on the GND plane of the antenna for lower band isolation improvement. The lower band of operation covers 827-853 MHz and the higher band covers 2.3-2.98 GHz. Two prototypes were investigated to access the effect of the isolation mechanism. Measured isolation improvement of 10 dBs was observed in the lower operating band while the improvement in the higher band was approximately 2.5 dBs. The isolation improvement was at the expense of 5% reduction in efficiency. The measured gain patterns as well MIMO figures of merits such as the correlation factor, TARC and MEG were investigated as well.
ISOLATION IMPROVEMENT IN A DUAL-BAND DUAL-ELEMENT MIMO ANTENNA SYSTEM USING CAPACITIVELY LOADED LOOPS
2012-11-24
PIER
Vol. 134, 227-246, 2013
download: 133
Limits of Negative Group Delay Phenomenon in Linear Causal Media
Miodrag Kandic Greg E. Bridges
Asymptotic limits of Negative Group Delay (NGD) in linear causal media satisfying Kramers-Kronig relations are investigated. Even though there is no limit on the NGD-bandwidth product of a linear medium, it is shown that the out-of-band to center frequency amplitude ratio, or out-of-band gain, increases with the NGD-bandwidth product, and is proportional to the amplitude of undesired transients when waveforms with defined "turn on/off" times propagate in the media. The optimal causal dispersion characteristic exhibiting NGD is obtained through Kramers-Kronig relations, which maximizes the NGD-bandwidth product as a function of the out-of-band gain. It is shown that the NGD-bandwidth product has an upper asymptotic limit proportional to the square root of the logarithm of the maximum out-of-band gain. The derived NGD-bandwidth upper asymptotic limit of the optimally engineered causal dispersion characteristic is validated with two examples of physical media, a Lorentzian dielectric medium, and an artificially fabricated loaded transmission line medium.
LIMITS OF NEGATIVE GROUP DELAY PHENOMENON IN LINEAR CAUSAL MEDIA
2012-11-24
PIER
Vol. 134, 209-226, 2013
download: 107
SAR Image Despeckling by Selective 3D Filtering of Multiple Compressive Reconstructed Images
Mahboob Iqbal Jie Chen Wei Yang Pengbo Wang Bing Sun
A despeckling technique based on multiple image reconstruction and selective 3-dimensional filtering is proposed. Multiple SAR images are reconstructed from a single SAR image by employing compressive sensing (CS) theory. In order to obtain multiple images from single SAR image, multiple subsets of pixels are selected from input SAR image by imposing restriction that each subset has at least 20% different pixels than any other subset. These subsets are taken as measurement vectors in CS framework to obtain multiple SAR images. A despeckled image is obtained by employing selective 3-dimensional filtering to multiple reconstructed SAR image. The proposed technique is tested on single look complex TerraSAT-X data set, and experimental results exhibit that the proposed technique outperformed benchmark despekling methods in terms of visual quality and despeckling quality metrics.
SAR IMAGE DESPECKLING BY SELECTIVE 3D FILTERING OF MULTIPLE COMPRESSIVE RECONSTRUCTED IMAGES
2012-11-24
PIER
Vol. 134, 189-208, 2013
download: 144
Development of a New Approach for High-Quality Quadrupling Frequency Optical Millimeter-Wave Signal Generation Without Optical Filter
Nael Ahmed Al-Shareefi Syed Idris Syed Hassan Mohd Fareq Bin Abd Malek Razali Ngah Syed Alwee Aljunid Rashid Ali Fayadh Jaafar Adhab Hasliza A. Rahim
In this paper, we propose a new approach to generate quadrupling-frequency optical millimeter-wave (mm-wave) signal with carrier suppression by using two parallel Mach-Zehnder modulators (MZMs) in Radio-over-fiber (RoF) system. Among the numerous properties of this approach, the most important is that a filterless optical mm-wave at 60 GHz with an optical sideband suppression ratio (OSSR) as high as 40 dB can be obtained when the extinction ratio of the MZM is 25 dB. Simplicity and cost-effectiveness have made this approach a compelling candidate for future wave-division-multiplexing RoF systems. Theoretical analysis is conducted to suppress the undesired optical sidebands for the high-quality generation of frequency quadrupling mm-wave signal. The simulation results show that a 60 GHz mm-wave is generated from a 15 GHz radio frequency (RF) oscillator with an OSSR as high as 40 dB and an radio frequency spurious suppression ratio (RFSSR) exceeding 35 dB without any optical or electrical filter when the extinction ratio of the MZM is 25 dB. Furthermore, the effect of the non-ideal RF-driven voltage as well as the phase difference of RF-driven signals applied to the two MZMs on OSSR and RFSSR is discussed and analyzed. Finally, we establish a RoF system through simulation to verify the transmission performance of the proposed scheme. The Q-factor performance and eye patterns are given.
DEVELOPMENT OF A NEW APPROACH FOR HIGH-QUALITY QUADRUPLING FREQUENCY OPTICAL MILLIMETER-WAVE SIGNAL GENERATION WITHOUT OPTICAL FILTER
2012-11-24
PIER
Vol. 134, 169-187, 2013
download: 137
Generalized Analytical Design of Broadband Planar Baluns Based on Wire-Bonded Multiconductor Transmission Lines
Juan-Jose Sanchez-Martinez Enrique Marquez-Segura
A novel generalized design procedure of broadband planar baluns based on wire-bonded multiconductor transmission lines (MTL) is presented hereby based on analytical equations. The proposed balun consists of two parts. The first one is an in-phase power divider, which equally splits the input power through its two outputs. The later are two MTLs with wire bonding between alternate conductors configured to introduce +90 and -90 degrees phase shift respectively, so that the balanced output signal has a 180 degree phase difference. In that sense, new closed-form design equations in order to calculate the design parameters of both multiconductor elements are obtained. These equations allow the proper dimensions of both MTLs to be computed irrespective of both the number of conductors and the coupling factor, and therefore, to determine the performance of the balun. The design procedure for wire-bonded MTL baluns has been assessed by means of full-wave electromagnetic simulations and by experimental work. In addition, the very good agreement between the theoretical results and measurements makes possible to define a time-saving design methodology.
GENERALIZED ANALYTICAL DESIGN OF BROADBAND PLANAR BALUNS BASED ON WIRE-BONDED MULTICONDUCTOR TRANSMISSION LINES