Vol. 161
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]
2018-05-02
PIER
Vol. 161, 125-133, 2018
download: 253
A Wide-Angle and Wide-Band Circular Polarizer Using a BI-Layer Metasurface
Bao-Qin Lin Jianxin Guo Yanwen Wang Zuliang Wang Baigang Huang Xiangwen Liu
In this work, a wide-angle and wide-band transmission-type circular polarizer based on a bi-layer anisotropic metasurface is proposed, in which the unit cell consists of two layers of identical patterned metal films deposited on the two sides of a homogeneous dielectric layer, and the geometric pattern of the metal film is a square aperture surrounding a concentric square-corner-truncated square patch. The simulated results show that the polarizer can realize a linear-to-circular polarization conversion at both x- and y-polarized incidences in the frequency range from 7.63 to 11.13 GHz with a relative bandwidth of 37.3%, and it can maintain a stable polarization conversion performance under large-range incidence angles. Moreover, it has no asymmetric transmission effect, and the transmission coefficients at x- and y-polarized incidences are completely equal. Finally, one experiment is carried out, and the simulated and measured results are almost in agreement with each other.
A WIDE-ANGLE AND WIDE-BAND CIRCULAR POLARIZER USING A BI-LAYER METASURFACE
2018-04-20
PIER
Vol. 161, 113-123, 2018
download: 116
Efficiency of Millimeter Wave Mobile Terminal Antennas with the Influence of Users
Rizwan Khan Azremi Abdullah Al-Hadi Ping Jack Soh
The effect of users on the efficiency of mobile terminal antennas at 15 GHz, 28 GHz and 60 GHz is studied in this paper. It is performed using three four-element planar arrays. The first operates at 15 GHz with a bandwidth of 0.74 GHz, the second at 28 GHz with a bandwidth of 2.5 GHz and finally the third antenna at 60 GHz with bandwidth of 12.5 GHz. The effect of a user's finger is studied when being placed on four different locations over each antenna element, with six distances between the antenna and user's finger. The losses due to the increased shadowing are studied in terms of radiation efficiency (RE), matching efficiency (ME) and two additional multiple-input-multiple-output (MIMO) parameters i.e., envelop correlation coefficient (ECC) and multiplexing efficiency (MUX). For antennas operating at 28 and 60 GHz, the minimum frequency shift is observed when the finger is placed at 1.5 mm distance from the antenna, whereas for 15 GHz, the minimum resonance shift is observed when the finger is at 2 mm distance. Losses of up to 80% and 70% are observed for RE and MUX, respectively, when the finger is placed at 0 mm for all antennas compared to the case without user (WU). Finally, it is observed that the ME and envelop correlation coefficient losses are insignificant regardless of the antenna and finger variation.
EFFICIENCY OF MILLIMETER WAVE MOBILE TERMINAL ANTENNAS WITH THE INFLUENCE OF USERS
2018-04-18
PIER
Vol. 161, 101-111, 2018
download: 146
Photo-Induced Electromagnetic Band Gap Structures for Optically Tunable Microwave Filters
Jun Ren Zhenguo Jiang Md. Itrat Bin Shams Patrick Fay Lei Liu
Electromagnetic band gap (EBG) structures offer unique solutions for effectively manipulating electromagnetic waves over a broad range of frequencies for a wide range of applications. However, most EBG designs reported so far either require sophisticated fabrication processes or have limited tunability and reconfigurability. In this paper, we investigate the potential to implement high performance tunable and reconfigurable EBG components using a novel optical control approach. This technology allows the generation of EBG structures through spatially-resolved photogeneration of free carriers in a semiconductor, without any complex fabrication processes. As a prototype demonstration, a reconfigurable microwave frequency tunable band-stop filter (BSF) based on photo-induced uniplanar EBG structures has been investigated through simulation. In this approach, the required EBG patterns are directly illuminated onto a Ge ground plane mounted to the bottom of a Duroid substrate for tunability using a digital light processing (DLP) projector. On the basis of HFSS simulations, the bandwidth of the BSF can be tuned by modifying the EBG pattern filling factor. The center frequency of the BSF could also be tuned from 8-12 GHz by adjusting the period of the EBG structure. In addition, two limiting factors, i.e., localized heating effects and finite lateral spatial resolution (due to carrier diffusion), that may affect the circuit performance in this technology have been investigated and discussed. By using a mesa-array structured ground plane, this approach is promising for developing tunable and reconfigurable circuits such as filters from the microwave to terahertz regimes.
PHOTO-INDUCED ELECTROMAGNETIC BAND GAP STRUCTURES FOR OPTICALLY TUNABLE MICROWAVE FILTERS
2018-04-13
PIER
Vol. 161, 87-100, 2018
download: 226
Towards Robust Human Millimeter Wave Imaging Inspection System in Real Time with Deep Learning
Chenyu Liu Ming-Hui Yang Xiao-Wei Sun
With the ever-growing requirements of human security check in public, near-field millimeter wave (MMW) imaging techniques have been developing rapidly in recent years. Due to the lack of MMW images, low resolution and indistinguishable texture in most MMW images, it is still a great challenge to do high performance object detection task on MMW images. In this paper, we propose a novel framework to automatically detect concealed weapons and potential dangerous objects based on a single human millimeter wave image, in which a deep convolutional neural network (CNN) is presented to simultaneously extract features, detect suspicious objects, and give the confidence score. Unlike traditional optical image level solutions, we comprehensively analyze the original MMW data for object representation, incorporate domain-specific knowledge to design and train our network. Moreover, combined with the modern focal loss theory, we devise an effective loss function elaborately to optimize our model. Experimental results on both our dataset and real world data show the effectiveness and improvement of our method compared with the state-of-the-arts.
TOWARDS ROBUST HUMAN MILLIMETER WAVE IMAGING INSPECTION SYSTEM IN REAL TIME WITH DEEP LEARNING
2018-04-05
PIER
Vol. 161, 57-85, 2018
download: 1155
CMOS Low Noise Amplifier Design for Microwave and mmWave Applications (Invited Review)
Xue Jun Li Yue-Ping Zhang
This paper reviews recent advances in the design of low noise amplifier (LNA) in complementary metal oxide semiconductor (CMOS) technology for radio transceivers at microwave and millimeter wave (mmWave) frequencies. First, the evolution of wireless communication systems and CMOS technology are briefly revisited to highlight the requirements of an LNA design. Then, key performance parameters and device circuit models are described. Next, we discuss typical LNA topologies, followed by those important design techniques, algorithms and concepts developed specifically for CMOS LNAs. Moreover, reported CMOS LNA designs are summarized, and future design issues are identified. Finally, we conclude the paper and briefly outline our future work on CMOS LNA designs.
CMOS LOW NOISE AMPLIFIER DESIGN FOR MICROWAVE AND MMWAVE APPLICATIONS (INVITED REVIEW)
2018-03-26
PIER
Vol. 161, 41-55, 2018
download: 219
A Low-Profile Pattern Reconfigurable Antenna System for Automotive MIMO Applications
Jerzy Kowalewski Jude Atuegwu Jonathan Mayer Tobias Mahler Thomas Zwick
This paper presents the design and evaluation of a compact antenna system with pattern reconfigurability at 2.6 GHz. The antenna is based on the concept of an electronically steerable parasitic array radiator (ESPAR), and its height is reduced by top loading. The antenna can generate 10 reconfigurable patterns with a maximal gain of 7.4 dBi. Furthermore, a multiple antenna system consisting of these antennas is proposed. The radiation patterns realized by this multiple-input-multiple-output (MIMO) system are optimized for automotive urban scenarios based on the results of previous research. The S-parameter measurement results of a fabricated prototype correlate with the simulation. Furthermore, 3D measurements of radiation patterns correspond very well with simulation and gain up to 8 dBi is obtained.
A LOW-PROFILE PATTERN RECONFIGURABLE ANTENNA SYSTEM FOR AUTOMOTIVE MIMO APPLICATIONS
2018-03-15
PIER
Vol. 161, 35-40, 2018
download: 462
Efficient Metasurface Rectenna for Electromagnetic Wireless Power Transfer and Energy Harvesting
Mohamed El Badawe Omar M. Ramahi
This work presents a design for a metasurface that provides near-unity electromagnetic energy harvesting and RF channeling to a single load. A metasurface and a feeding network were designed to operate at 2.72 GHz to deliver the maximum power to a single load. Numerical simulations show that the metasurface can be highly efficient delivering the maximum captured power to one load using a corporate feed network reaching Radiation-to-RF conversion efficiency as high as 99%. A prototype was fabricated incorporating a rectification circuit. Measurements demonstrated that the proposed metasurface harvester provides Radiation-to-DC conversion efficiency of more than 55%, which is significantly higher than earlier designs reported in the literature.
EFFICIENT METASURFACE RECTENNA FOR ELECTROMAGNETIC WIRELESS POWER TRANSFER AND ENERGY HARVESTING
2018-03-10
PIER
Vol. 161, 19-33, 2018
download: 206
Fast Low-Frequency Surface Integral Equation Solver Based on Hierarchical Matrix Algorithm
Ting Wan Qi Dai Weng Cho Chew
A fast low-frequency surface integral equation solver based on hierarchical matrix algorithm is proposed. First, the augmented electric field integral equation (A-EFIE) formulation is introduced to eliminate the low-frequency breakdown of traditional EFIE. To deal with large-scale problems, the low-frequency multilevel fast multipole algorithm (LF-MLFMA) is employed to construct a hierarchical (H-) matrix representation of the A-EFIE system matrix. Moreover, a recompression method is developed to further compress the H-matrix generated by LF-MLFMA. The H-matrix-based triangular factorization algorithm can be performed with almost linear computational complexity and memory requirement, which produces a fast direct solver for multiple right-hand-side (RHS) problems, and a good preconditioner to accelerate the convergence rate of an iterative solver. Numerical examples demonstrate the effectiveness of the proposed method for the analysis of various low-frequency problems.
FAST LOW-FREQUENCY SURFACE INTEGRAL EQUATION SOLVER BASED ON HIERARCHICAL MATRIX ALGORITHM
2018-03-05
PIER
Vol. 161, 11-18, 2018
download: 197
Exploratory Study on Light-Sheet Based Three-Dimensional Surface Topography
Fuhong Cai Jie Chen Chunling Zhou Xuan Zhu Sailing He
Light-sheet microscopy has attracted considerable attention since it is a fluorescence imaging technique with rapid optical sectioning capabilities for transparent sample. In our study, we report a new application based on light-sheet microscopy for exploratory investigating three-dimensional surface topography of opaque sample. Instead of using inelastic scattering fluorescent signal, our method utilizes the elastic scattering light from the surface of opaque sample, which is illuminated by a light sheet generated by a cylindrical lens. Through a simple structural modification by removing the fluorescent filter, the orthogonally imaging module can capture the elastic scattering image. As the opaque sample is scanned by a motorized stage, the light-sheet microscope acquires a serial of sectional images, which can be stitched to be a three-dimensional surface topography image. This method also offers the opportunity to visualize 3D fingerprint on micron level. Therefore, this technique may be useful in industry and biomedical field for the measurement of surface microstructure.
EXPLORATORY STUDY ON LIGHT-SHEET BASED THREE-DIMENSIONAL SURFACE TOPOGRAPHY
2018-02-28
PIER
Vol. 161, 1-10, 2018
download: 218
Design and Implementation of High Efficiency and Broadband Transmission-Type Polarization Converter Based on Diagonal Split-Ring Resonator
Rui Zhao Hai-Yan Chen Linbo Zhang Fengxia Li Peiheng Zhou Jianliang Xie Long-Jiang Deng
In this paper, the design and implementation of a three-layer linear polarization converter having broadband and asymmetric transmission (AT) properties is demonstrated. A 3.2 mm thick transmission-type polarization converter with two separate operating frequency bands is obtained with a cut-wire sandwiched by two layers of diagonal split-ring resonator (DSRR). The asymmetric transmission property can be realized by rotating the upper and lower DSRR dislocation, and its physical mechanism can be explicated by the Fabry-Pérot-like interference effect. Experimental results are presented and compared to numerical simulations, and they demonstrate that the proposed polarization converter has a significantly polarization conversion ratio over 0.8 in frequency bandwidths 8-11 GHz and 17-21 GHz for the forward and backward incidences. The proposed polarization converter has a great potential to be used as an asymmetric transmission radome or diode-like device in microwave domain.
DESIGN AND IMPLEMENTATION OF HIGH EFFICIENCY AND BROADBAND TRANSMISSION-TYPE POLARIZATION CONVERTER BASED ON DIAGONAL SPLIT-RING RESONATOR