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oe1(光电查) - 科学论文

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出版时间
  • 2018
研究主题
  • Schottky diodes
  • frequency multipliers
  • submillimeter-wave technology
  • terahertz technology.
  • Submillimeter-wave sources
应用领域
  • Optoelectronic Information Science and Engineering
机构单位
  • California Institute of Technology
201 条数据
?? 中文（中国） ▾

  • [IEEE 2019 IEEE International Electron Devices Meeting (IEDM) - San Francisco, CA, USA (2019.12.7-2019.12.11)] 2019 IEEE International Electron Devices Meeting (IEDM) - Integrated DFB Laser Diode and High-efficiency Mach-Zehnder Modulator using Membrane III-V Semiconductors on Si Photonics Platform

    摘要： This paper presents a 3-D statistical channel impulse response (IR) model for urban line of sight (LOS) and non-LOS channels developed from 28- and 73-GHz ultrawide-band propagation measurements in New York City, useful in the design of 5G wireless systems that will operate in both the ultra-high frequency/microwave and millimeter-wave (mmWave) spectrum to increase channel capacities. A 3GPP-like stochastic IR channel model is developed from measured power delay profiles, angle of departure, and angle of arrival power spectra. The extracted statistics are used to implement a channel model and simulator capable of generating 3-D mmWave temporal and spatial channel parameters for arbitrary mmWave carrier frequency, signal bandwidth, and antenna beamwidth. The model presented here faithfully reproduces realistic IRs of measured urban channels, supporting air interface design of mmWave transceivers, filters, and multi-element antenna arrays.

    关键词： 28 GHz,multipath,time cluster spatial lobe (TCSL),spatial lobe (SL),statistical simulator,5G,spatial channel model (SCM),73 GHz,Channel model,millimeter-wave (mmWave) propagation,3-D ray-tracing,time cluster (TC),impulse response (IR)

    更新于2025-09-23 15:19:57

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - InGaN Quantum Dots for Intermediate Band Solar Cells

    摘要： A novel simple approach to the verification process for millimeter-wave vector network analyzer waveguide calibration is reported using a single reconfigurable component verification kit. Conventional techniques require multiple verification components and these only exist commercially for operation up to 110 GHz. At millimeter-wave frequencies, the use of multiple components can lead to significant errors due to imperfections in waveguide flange misalignments during the multiple component connections. The reconfigurable component is designed so that its electrical properties can be changed quickly to a broad range of predetermined values without introducing additional errors due to changes in flange alignment. Once connected, the component can be reconfigured to introduce relative changes in the reflected and transmitted signals. For millimeter-wave metrology, where mechanical precision is of paramount importance, this single-component verification approach represents an attractive solution. A proof-of-concept verification process is described, based on full-wave electromagnetic modeling, hardware implementation, and validation measurements using standard WR-15 waveguide (50–75 GHz).

    关键词： verification,millimeter-wave,Measurement,vector network analyzer (VNA),reconfigurable,rectangular waveguide

    更新于2025-09-23 15:19:57

  • [IEEE 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Guangzhou, China (2019.5.19-2019.5.22)] 2019 International Conference on Microwave and Millimeter Wave Technology (ICMMT) - Integrated Substrate Gap Waveguide for 5G Microwave and Millimeter-Wave Components

    摘要： This work reviews fundamentals of integrated substrate gap waveguide (ISGW) in structure and operation principle. The most important aspect of ISGW is that not only circuit functions such as antennas, filters, and power dividers can be designed and implemented, but also inherent self-packaging function of the circuit is obtained. Compared with substrate integrated waveguide (SIW), ISGW introduces less transmission loss, and additional design freedoms that may result in better performance of a circuit. Moreover, examples of ISGW based antennas, filters and power couplers are given to show advantages of ISGW. It is believed that ISGW has high potential for 5G integrated microwave and millimeter-wave circuits.

    关键词： 5G,millimeter wave,filters,microwave,couplers,self packaging,antennas,passive components

    更新于2025-09-23 15:19:57

  • [IEEE 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - Dhaka, Bangladesh (2019.12.24-2019.12.25)] 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - A New Medium Voltage Modular Multilevel Inverter with Advanced Carrier-Based Pulse Width Modulation for Solar Photovoltaic Systems

    摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.

    关键词： analog precoding and combining,interference alignment,energy efficiency,Millimeter-wave communication,multiple-input multiple-output (MIMO) system

    更新于2025-09-23 15:19:57

  • Real-time Concealed Object Detection from Passive Millimeter Wave Images Based on the YOLOv3 Algorithm

    摘要： The detection of objects concealed under people’s clothing is a very challenging task, which has crucial applications for security. When testing the human body for metal contraband, the concealed targets are usually small in size and are required to be detected within a few seconds. Focusing on weapon detection, this paper proposes using a real-time detection method for detecting concealed metallic weapons on the human body applied to passive millimeter wave (PMMW) imagery based on the You Only Look Once (YOLO) algorithm, YOLOv3, and a small sample dataset. The experimental results from YOLOv3-13, YOLOv3-53, and Single Shot MultiBox Detector (SSD) algorithm, SSD-VGG16, are compared ultimately, using the same PMMW dataset. For the perspective of detection accuracy, detection speed, and computation resource, it shows that the YOLOv3-53 model had a detection speed of 36 frames per second (FPS) and a mean average precision (mAP) of 95% on a GPU-1080Ti computer, more e?ective and feasible for the real-time detection of weapon contraband on human body for PMMW images, even with small sample data.

    关键词： YOLOv3,real-time,neural network,concealed object detection,deep learning,passive millimeter wave

    更新于2025-09-23 15:19:57

  • [IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - The Response Characteristics of Dielectric Logging in Anisotropic Formation

    摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.

    关键词： Millimeter-wave communication,energy efficiency,interference alignment,analog precoding and combining,multiple-input multiple-output (MIMO) system

    更新于2025-09-23 15:19:57

  • [IEEE ICASSP 2018 - 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - Calgary, AB (2018.4.15-2018.4.20)] 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - Dithered Beamforming for Channel Estimation in Mmwave-Based Massive Mimo

    摘要： In this work we consider the challenging problem of channel estimation at the receiver of a massive multiple-input multiple-output system with hybrid analog/digital beamforming and low-resolution quantization. We propose a dithered beamforming architecture, where random control signals are injected to the analog part of the receiver beamformer and to the analog-to-digital converters to introduce randomness into the signal capturing process and combat the stair-case quantization effects. The statistical properties of the dithered output are captured via an Expectation-Maximization approximation of the maximum a-posteriori estimator. A low-complexity algorithm is proposed which exhibits performance close to the oracle-based least-squares estimation of the sparse channel.

    关键词： low resolution analog-to-digital converter (ADC),hybrid analog/digital beamforming,millimeter wave (mmWave) massive MIMO

    更新于2025-09-23 15:19:57

  • Joint FSO Fronthaul and Millimeter-Wave Access Link Optimization in Cloud Small Cell Networks: A Statistical-QoS Aware Approach

    摘要： We investigate resource optimization for downlink cloud small cell network where the baseband unit pool communicates with the buffer-aided small remote radio heads (SRRHs) through free space optical fronthaul, and SRRHs transmit to the user equipments (UEs) by using time division multiplexing based millimeter wave access links. Our objective is to maximize the supportable aggregate data arrival rate in the network by exploiting inter-dependence of fronthaul and access links. Towards this objective, we consider maximum acceptable end-to-end queue-length bound violation probability constraints, load-balancing constraints in the access link, fronthaul link selection constraints, and transmit power budget constraints of fronthaul and access links. Since the joint fronthaul and access link optimization is a non-convex and combinatorial problem, we develop iterative solution by decomposing the original optimization problem into two sub-problems. The first sub-problem optimally obtains fronthaul and access link power allocation and fronthaul link selection by using Lagrangian dual decomposition and canonical one-to-one matching techniques. By employing Lagrangian dual decomposition and alternating optimization techniques, the second sub-problem obtains near optimal data arrival rate for each UE, UE-SRRH associations, fronthaul rate allocation among the transmitted data for the UEs, and transmission duration scheduling in millimeter wave access link. An algorithm of polynomial complexity is developed in order to determine the supportable aggregate data arrival rate by considering statistical quality-of-service requirements, and its convergence is proved. Simulation results depict that the proposed scheme significantly improves the aggregate data arrival rate over several benchmark schemes.

    关键词： statistical-QoS,fronthaul,millimeter wave,optimization,Free space optical communication

    更新于2025-09-19 17:15:36

  • [IEEE 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Boston, MA, USA (2018.7.8-2018.7.13)] 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Wideband Circularly-Polarized 3D Antenna Array for Millimeter-Wave Applications

    摘要： This paper presents a novel millimeter-wave wideband circularly-polarized 3D helical array antenna that works at 30 GHz. To design an antenna with wide circular polarization (CP) bandwidth, a 2 x 2 axial-mode helical structure is fed by using a sequential phase feeding network. The antenna array covers a wide frequency band from 26.4 GHz to 34 GHz with an achieved maximum gain of 11 dB and an axial ratio of less than 3 dB in the whole band. Moreover, the radiation pattern of the proposed antenna has a right-handed circular polarization (RHCP) with side-lobe level below -10 dB. Subsequently, the proposed antenna array can be a good candidate for millimeter-wave communication systems around 30 GHz.

    关键词： 3D antenna,Antenna array,circular polarization (CP),helix,millimeter wave

    更新于2025-09-19 17:15:36

  • [IEEE 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Boston, MA, USA (2018.7.8-2018.7.13)] 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting - Computational Millimeter-wave Spotlight Imaging using Holographic Metasurface Antennas

    摘要： In this paper, a spotlight imaging system integrated with a frequency-diverse aperture is presented for security-screening applications. The spotlight imager consists of holographic metasurface antennas that can dynamically be tuned to radiate spotlight patterns allowing the extraction of high-resolution images from a constrained field-of-view (FOV). The spotlight aperture operates at a single frequency, 75 GHz, within the W-band frequency regime (75 – 110 GHz) and is used for the identification of threat objects while the frequency-diverse aperture operates at K-band frequencies (17.5 – 26.5 GHz) and is used for detection purposes, determining the constrained FOV to be imaged using the spotlight imager at high resolution.

    关键词： spotlight,metamaterial,metasurface,millimeter-wave,microwaves,imaging,focusing

    更新于2025-09-19 17:15:36