Vol. 169
Latest Volume
All Volumes
PIER 180 [2024] 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]
2020-12-31
PIER
Vol. 169, 117-127, 2020
download: 660
A Parameter-Free Calibration Process for a Scheimpflug LIDAR for Volumetric Profiling
Longqiang Luo , Xiang Chen , Zhanpeng Xu , Shuo Li , Yaoran Sun and Sailing He
Scheimpflug LIDAR has attracted considerable attention in the recent years, and has been widely applied in many fields due to its infinite depth of field. In this study, we reconstruct a series of formulas to demonstrate the Scheimpflug principles, with reference at the hinge point. These formulas based on directly measurable parameters are simple in form. Base on this, we report a new calibration for the Scheimpflug system, without measuring the instrument parameters. We also confirm that the result of calibration is accordance with the actual setting of the system. To take full advantage of the infinite depth of field of the Scheimpflug system, we have designed and carried out the system, combining with a rotary stage, to obtain the entire volumetric profile for a target of interest in a cycle rotation. To the best of our knowledge, this is the first time Scheimpflug system is utilized to perform a three-dimensional volumetric profile measurement.
A PARAMETER-FREE CALIBRATION PROCESS FOR A SCHEIMPFLUG LIDAR FOR VOLUMETRIC PROFILING
2020-12-31
PIER
Vol. 169, 103-115, 2020
download: 918
Wideband RCS Reduction of High Gain Fabry-Perot Antenna Employing a Receiver-Transmitter Metasurface
Peng Xie , Guang-Ming Wang , Hai-Peng Li , Ya-Wei Wang and Binfeng Zong
This paper presents a high gain Fabry-Perot antenna with radar cross section (RCS) reduction property. A receiver-transmitter metasurface is designed and used as the partially reflective surface (PRS) of the antenna to realize high gain and wideband RCS reduction. Firstly, the working principle of the unit cell is similar to the reception and radiation of two patch antennas. The unit cell is designed to present high reflectivity through tuning the impedance matching between two patches. This can ensure that the antenna obtains high gain. Then, the ground plane in the middle makes the reflection phase from different sides of the unit cell be tuned independently. Two unit cells with same reflection phase from the bottom side and 180° reflection phase difference from the top side are obtained through tuning the size of the transmitter patch. With the improved chessboard arrangement of these two unit cells, the incident wave can be scattered into many directions. So the metasurface presents a good RCS reduction property. More importantly, thanks to the high reflectivity of the metasurface, almost all the electromagnetic waves from the outside are reflected and rarely enter the cavity. Therefore, the antenna achieves good in band RCS reduction. The measured results of the fabricated antenna agree well with the simulated ones, which verify the correctness of the design. The antennas reaches the maximum gain of 18.2 dBi at 10 GHz. Wideband RCS reduction and good in band RCS reduction are also obtained by the antenna.
WIDEBAND RCS REDUCTION OF HIGH GAIN FABRY-PEROT ANTENNA EMPLOYING A RECEIVER-TRANSMITTER METASURFACE
2020-12-31
PIER
Vol. 169, 87-101, 2020
download: 857
Electromagnetic-Circuital-Thermal Multiphysics Simulation Method: a Review (Invited)
Huan Huan Zhang , Pan Pan Wang , Shuai Zhang , Long Li , Ping Li , Wei E. I. Sha and Li Jun Jiang
Electromagnetic-circuital-thermal multiphysics simulation is a very important topic in the field of integrated circuit (IC), microwave circuits, antennas, etc. This paper gives a comprehensive review of the state of the art of electromagnetic-circuital-thermal multiphysics simulation method. Most efforts were focused on electromagnetic-circuital co-simulation and electromagnetic-thermal co-simulation. A brief introduction of related theory like governing equations, numerical methods, and coupling mechanisms is also included.
ELECTROMAGNETIC-CIRCUITAL-THERMAL MULTIPHYSICS SIMULATION METHOD: A REVIEW (INVITED)
2020-12-31
PIER
Vol. 169, 73-86, 2020
download: 885
Distinguishing Bipolar Depression from Major Depressive Disorder Using fNIRS and Deep Neural Network
Tengfei Ma , Hailong Lyu , Jingjing Liu , Yuting Xia , Chao Qian , Julian Evans , Weijuan Xu , Jianbo Hu , Shaohua Hu and Sailing He
A variety of psychological scales are utilized at present as the most important basis for clinical diagnosis of mood disorders. An experienced psychiatrist assesses and diagnoses mood disorders based on clinical symptoms and relevant assessment scores. This symptom based clinical criterion is limited by the psychiatrist's experience. In practice, it is difficult to distinguish the patients with bipolar disorder with depression episode (bipolar depression, BD) from those with major depressive disorder (MDD). The functional near-infrared spectroscopy (fNIRS) technology is commonly used to perceive the emotions of a human. It measures the hemodynamic parameters of the brain, which correlate with cerebral activation. Here, we propose a machine learning classification method based on deep neural network for the brain activations of mood disorders. Large time scale connectivity is determined using an attention long short term memory neural network and short-time feature information are considered using the InceptionTime neural network in this method. Our combined method is referred to as AttentionLSTM-InceptionTime (ALSTMIT). We collected fNIRS data of 36 MDD patients and 48 BD patients who were in the depressed state. All the patients were monitored by fNIRS during conducting the verbal fluency task (VFT). We trained the model with the ALSTMIT network. The algorithm can distinguish the two types of patients effectively: the average accuracy of classification on the test set can reach 96.2% stably. The classification can provide an objective diagnosis tool for clinicians, and this algorithm may be critical for the early detection and precise treatment for the patients with mood disorders.
DISTINGUISHING BIPOLAR DEPRESSION FROM MAJOR DEPRESSIVE DISORDER USING FNIRS AND DEEP NEURAL NETWORK
2020-12-30
PIER
Vol. 169, 59-71, 2020
download: 1364
A Review of Algorithms and Hardware Implementations in Electrical Impedance Tomography (Invited)
Zheng Zong , Yusong Wang and Zhun Wei
In recent years, electrical impedance tomography (EIT) has attracted intensive interests due to its noninvasive, ionizing radiation-free, and low-cost advantages, which is promising for both biomedical imaging and industry nondestructive tests. The purpose of this paper is to review state-of-the-art methods including both algorithms and hardwares in EIT. More specifically, for the advanced reconstruction algorithms in mainstream, we offer some insights on classification and comparison. As for the measurement equipment, the structure, configuration modes, and typical systems are reviewed. Furthermore, we discuss the limitations and challenges in EIT technique, such as low-spatial resolution and nonlinear-inversion problems, where future directions, such as solving EIT problems with deep learning, have also been addressed.
A REVIEW OF ALGORITHMS AND HARDWARE IMPLEMENTATIONS IN ELECTRICAL IMPEDANCE TOMOGRAPHY (INVITED)
2020-11-30
PIER
Vol. 169, 33-43, 2020
download: 599
One-Way Topological States Along Vague Boundaries in Synthetic Frequency Dimensions Including Group Velocity Dispersion (Invited)
Qingrou Shan , Danying Yu , Guangzhen Li , Luqi Yuan and Xianfeng Chen
We recently proposed a two-dimensional synthetic space including one spatial axis and one synthetic frequency dimension in a one-dimensional ring resonator array [Opt. Lett. 41, 741 (2016)]. Nevertheless, the group velocity dispersion (GVD) of the waveguides that compose rings was ignored for simplicity. In this paper, we extend the previous work and study the topological one-way edge states in such a synthetic space involving GVD. We show that the GVD brings a natural vague boundary in the frequency dimension, so the topological edge state still propagates at several frequency modes unidirectionally along the spatial axis. Positions of such vague boundary can be controlled by changing the magnitude of the GVD. In particular, a relatively strong GVD can degrade this two-dimensional synthetic space to one-dimensional spatial lattice, but yet the one-way state is still preserved in simulations. Our work therefore exhibits the impact of the GVD on topological photonics in the synthetic space, which will be important for future practical experimental implementations.
ONE-WAY TOPOLOGICAL STATES ALONG VAGUE BOUNDARIES IN SYNTHETIC FREQUENCY DIMENSIONS INCLUDING GROUP VELOCITY DISPERSION (INVITED)
2020-11-25
PIER
Vol. 169, 25-32, 2020
download: 817
Designer Surface Plasmons Enable Terahertz Cherenkov Radiation (Invited)
Jie Zhang , Xiaofeng Hu , Hongsheng Chen and Fei Gao
Cherenkov radiation (CR) is a promising method to generate high-power terahertz (THz) electromagnetic (EM) waves, which are highly desired in numerous practical applications. For the purpose of economy energy, naturally occurred materials with flat surface (e.g. graphene), which can support highly-confined surface-plasmon-polariton (SPP) modes, have been proposed to construct high-efficiency terahertz CR source; however, these emerging materials cannot be easily fabricated nor flexibly designed. Here, we propose a designer-SPP metamaterial scheme to pursue terahertz CR. The metamaterial is a structure-decorated metal surface, which is compatible with planar fabrication, and can support SPP-like EM modes in terahertz frequencies, also named as designer SPP. Due to the structure dependence of designer SPP, its dispersions can be flexibly designed by changing the structure geometries as well as choosing proper dielectric medias. Numerical results clearly demonstrated this scheme. Our proposal may promise future high-efficiency and intense THz source with design flexibilities.
DESIGNER SURFACE PLASMONS ENABLE TERAHERTZ CHERENKOV RADIATION (INVITED)
2020-11-25
PIER
Vol. 169, 17-23, 2020
download: 636
Multi-Laser Scanning Confocal Fluorescent Endoscopy Scheme for Subcellular Imaging (Invited)
Xiaomin Zheng , Xiang Li , Qiao Lin , Jiajie Chen , Yueqing Gu and Yonghong Shao
Fluorescence confocal laser scanning endomicroscopy is a novel tool combining confocal microscopy and endoscopy for in-vivo subcellular structure imaging with comparable resolution as the traditional microscope. In this paper, we propose a three-channel fluorescence confocal microscopy system based on fiber bundle and two excitation laser lines of 488nm and 650nm. Three fluorescent photomultiplier detecting channels of red, green and blue can record multi-color fluorescence signals from single sample site simultaneously. And its ability for in-vivo multi-channel fluorescence detection at subcellular level is verified. Moreover, the system has achieved an effective field of view of 154μm in diameter with high resolution. With its multi-laser scanning, multi-channel detection, flexible probing, and in-vivo imaging abilities it will become a powerful tool in bio-chemical research and diagnostics, such as the investigation of the transport mechanism of nano-drugs in small animals.
MULTI-LASER SCANNING CONFOCAL FLUORESCENT ENDOSCOPY SCHEME FOR SUBCELLULAR IMAGING (INVITED)
2020-11-06
PIER
Vol. 169, 1-15, 2020
download: 599
The Multilevel Fast Physical Optics Method for Calculating High Frequency Scattered Fields
Zhiyang Xue , Yu Mao Wu , Weng Cho Chew , Ya-Qiu Jin and Amir Boag
The multilevel fast physical optics (MLFPO) is proposed to accelerate the computation of the fields scattered from electrically large coated scatterers. This method is based on the quadratic patch subdivision and the multilevel technology. First, the quadratic patches are employed rather than the planar patches to discretize the considered scatterer. Hence, the number of the contributing patches is cut dramatically, thus making the workload of the MLFPO method much lower than that of the traditional Gordon's method. Next, the multilevel technology is introduced in this work to avoid calculating the physical optics scattered fields from the considered scatterer directly, so that the proposed algorithm can significantly reduce the computational complexity. Finally, numerical results have demonstrated the accuracy and efficiency of the MLFPO method based on the quadratic patches.
THE MULTILEVEL FAST PHYSICAL OPTICS METHOD FOR CALCULATING HIGH FREQUENCY SCATTERED FIELDS
2020-12-12
PIER
Vol. 169, 45-57, 2020
download: 1081
Rotman Lens Design with Wideband DRA Array
Mohammad Ranjbar Nikkhah , Manish Hiranandani and Ahmed A. Kishk
For rapid Rotman lens design, the symmetry plane is utilized to reduce the structure size by employing the odd and even mode characteristics. Solutions of half the structure for odd and even modes (short and open walls or electrical and magnetic walls, respectively) are much more efficient than the one-time solution for the whole structure. Then, s-parameters from both solutions are processed to obtain the s-parameters of the full lens. To support the wideband and wide scanning range, DRA array is used because of its ability to support these characteristics. Two examples are considered. The first example that employs four cylindrical DRA elements is built and measured to test the concept of terminating the dummy ports by absorbing materials instead of matching loads. This termination tremendously simplifies the structure and reduces the cost by saving the terminating connectors and the matching loads. Here, thin planar absorbing material is used on top of the microstrip lines of the dummy ports. The simulated and measured results are in good agreement. The second example utilizes 8 rectangular DRA array elements and is studied numerically.
ROTMAN LENS DESIGN WITH WIDEBAND DRA ARRAY