- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - High color rendering index white LEDs fabricated using InP/ZnS green-emitting quantum dots and InP/ZnSe/ZnS red-emitting quantum dots
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 ultrawideband 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： 5G,28 GHz,3-D ray-tracing,multipath,time cluster (TC),spatial lobe (SL),millimeter-wave (mmWave) propagation,statistical simulator,spatial channel model (SCM),time cluster spatial lobe (TCSL),Channel model,impulse response (IR),73 GHz
更新于2025-09-16 10:30:52
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[IEEE 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - Paris, France (2019.9.1-2019.9.6)] 2019 44th International Conference on Infrared, Millimeter, and Terahertz Waves (IRMMW-THz) - A Compact Butler Matrix Design Based on Metallic Nanowire Filled Membrane Technology and Tunable Phase Shifter at 160 GHz
摘要： This paper presents the design of a planar miniaturized 4x4 Butler matrix, with implementation of 4 tunable 135° delay line phase shifters for a 160 GHz application. The Butler matrix and phase shifters are both realized with a metallic nanowire filled slow-wave alumina membrane microstrip line to miniaturize the size. Tunability is achieved by filling in a microwave liquid crystal. Comparing with commonly used corporate feed network, the simulation results show such a Butler matrix with 135°-phase shifters has less insertion loss and reduced size.
关键词： 160 GHz,slow-wave alumina membrane,Butler matrix,metallic nanowire,phase shifters,liquid crystal
更新于2025-09-16 10:30:52
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[IEEE 2019 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - Qingdao, China (2019.9.18-2019.9.20)] 2019 International Workshop on Electromagnetics: Applications and Student Innovation Competition (iWEM) - A Miniaturized Coplanar Waveguide-fed Antenna for Implantable Application at ISM Band
摘要： This paper proposes a novel implantable antenna design for biomedical applications. The antenna is designed to operate at 2.45 GHz, which is a common frequency for biomedical telemetry. The proposed antenna has a small size of 10 mm × 10 mm × 1.27 mm and is printed on a Rogers RO3210 substrate. The antenna is fed by a 50 Ω coaxial probe and is designed to be implanted in the human body. The performance of the antenna is evaluated in terms of return loss, radiation pattern, and specific absorption rate (SAR). The results show that the proposed antenna has a good impedance matching and radiation performance, and the SAR values are within the safety limits.
关键词： Specific absorption rate,Implantable antenna,Rogers RO3210,Biomedical telemetry,2.45 GHz
更新于2025-09-16 10:30:52
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High power GHz femtosecond laser for ablation efficiency increase
摘要： Nowadays the relevance and the robustness of ultrafast lasers are well established for many industrial applications. The main limitation to the penetration of femtosecond processing in the industrial manufacturing market is the insufficient productivity compared to the needs of the application markets and alternative technologies. Increasing the power, pulse energy or repetition rate, of femtosecond lasers has been a general trend in in order to comply to the needs of the market for higher throughput. One of the strategies of increasing the power has resulted in the development of a GHz femtosecond laser. When increasing the repetition rate during the process beyond several hundred kHz, the delay between the laser pulses is less than the thermal relaxation time and there is thermal accumulation in the target material. The resulting rise in temperature leads to an ablation threshold lowering. The authors report on a simple and easy-to-use GHz amplified femtosecond laser source. The laser source is based on a passively mode-locked oscillator with a near GHz repetition rate. GHz pulses are then selected, and the obtained bursts of pulses are further amplified in a high-power amplifier chain. The presented GHz femtosecond laser source is used with a galvanometric scanner to perform ablation experiments on copper, aluminum, and stainless steel. Specific ablation rates of 0.7, 2.3, and 1.4 (mm3/min)/W are reached. The role of the important experimental parameters, such as the number of sub-pulses in the burst, is highlighted. Thanks to a specific ablation scheme in the GHz mode, the ablation efficiency is then comparable to the case of single nanosecond pulses, but with the usual quality of femtosecond processing.
关键词： ultrashort pulse,efficiency,GHz,high power,ablation,Amplitude,laser,femtosecond
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE/MTT-S International Microwave Symposium - IMS 2019 - Boston, MA, USA (2019.6.2-2019.6.7)] 2019 IEEE MTT-S International Microwave Symposium (IMS) - W-band Finite Ground Coplanar Waveguide (FG-CPW) using Laser Enhanced Direct-Print Additive Manufacturing (LE-DPAM)
摘要： Design, fabrication, and measurement of finite ground coplanar waveguides (FG-CPWs) operating up to 110 GHz is demonstrated using additive manufacturing (AM) technology. FG-CPWs were fabricated using laser enhanced direct-print additive manufacturing, where laser-machining at 355 nm or 1064 nm wavelength was employed along with fused deposition modeling and micro-dispensing in a single digital manufacturing platform. This approach provides high dimensional accuracy that is required by mm-wave packaging systems. The characterization of laser machining at wavelengths of both 355 nm and 1064 nm was examined with specific focus on the feature size and dimensional accuracy. Several FG-CPW designs for 50 and 60 ohms are characterized and compared against a FG-CPW line on a commercially available calibration substrate. Attenuation as low as ~0.3 dB/mm at 110 GHz is achieved. To the best of the authors’ knowledge, this is the first reported experimental result for transmission lines at W-band using laser enhanced direct-print additive manufacturing (LE-DPAM).
关键词： transmission lines,W-band,laser machining,additive manufacturing,FG-CPW,millimeter wave,3D Printing,110 GHz
更新于2025-09-12 10:27:22
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Low power sensor node with photovoltaic power supply for radio-based process monitoring
摘要： This paper presents the idea of improving existing process monitoring systems for drilling, milling or threading by employing a novel communication technology as well as energy harvesting methods. An overview of the system including sensor node, energy supply and communication technology is given. The radio transmission methods are investigated in terms of power consumption in order to define requirements for the power supply. Fundamental measurements to characterize the behavior of different types of solar cells under artificial light are performed. Based on the results, two designs of sensor node prototypes are presented. The optical power supply and the energy harvesting system for the demonstrators are shown in detail.
关键词： optical power supply,process monitoring,24 GHz RFID,wireless sensor node,energy harvesting,RF communication
更新于2025-09-12 10:27:22
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[IEEE 2019 IEEE/MTT-S International Microwave Symposium - IMS 2019 - Boston, MA, USA (2019.6.2-2019.6.7)] 2019 IEEE MTT-S International Microwave Symposium (IMS) - 30Gb/s 60.2mW 151GHz CMOS Transmitter/Receiver with Digitally Pre-Distorted Current Mode PAM-4 Modulator for Plastic waveguide and Contactless Communications
摘要： 151 GHz CMOS transmitter and receiver are presented for ultra-short distance (~1 mm) contactless connection and plastic waveguide communications. To continue to scale the communication bandwidth, the 4-level pulse amplitude modulation (PAM-4) is utilized by implementing a current-mode PAM-4 modulator in the transmitter. The transmitter and receiver suffer non-linear characteristics and create amplitude distortions on PAM-4 signaling. A digital pre-distortion circuit is integrated in the PAM-4 modulator to correct such system non-idealities. 151 GHz antennas are realized on FR4HR substrate and used as air-to-air/chip-to-waveguide couplers. On top of contactless connection and plastic ribbon waveguide, plastic-embedded PCB channels are introduced by exploiting copper-coated slots on PCB and plastic ribbons to communicate through PCB substrates. The transmitter and receiver are fabricated in 28-nm CMOS process. The demonstrated system consumes 60.2 mW under 1.2 V supply while transferring 30 Gb/s of PAM-4 data, achieving 2.01 pJ/bit energy efficiency.
关键词： 151 GHz transmitter/receiver,PAM-4 modulation,contactless communication,plastic-embedded PCB,digital pre-distortion,plastic waveguide
更新于2025-09-12 10:27:22
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Ghz-Bursts and Ultrafast External Modulation of Femtosecond Fiber Lasers with kW Average Power Levels
摘要： State-of-the-art ultrafast materials processing applications impose strong requirements on the driving laser systems. For novel ablation schemes GHz-bursts are necessary to operate ideally [1,2]. Additionally, fast modulation and control of these pulse trains is required allowing for both high-power operation (kW of average powers and mJ pulse energies) and, ideally, pulse-to-pulse amplitude control. Here we present novel solutions to address these demands based on fiber-laser technology and coherent beam combination. A standard approach to generate GHz-pulse bursts is to use a seed oscillator with a GHz repetition rate emitting a continuous pulse train and employ a pulse picker to generate the burst afterwards. Although this approach is easy to implement, it is relatively inflexible and imposes strong requirements on the pulse picker. The approach presented herein bases on a state-of-the-art MHz-level oscillator followed by a standard pulse picker. The pulse burst is generated using cascaded fiber-based delay lines (see Fig. 1). This method allows for intra-burst repetition rates >10GHz with variable pulse numbers at flexible repetition rates. Furthermore, the implementation of ultra-fast switches into high-power material processing devices is of high demand. Although there has been progress in recent years, switching and modulation of high-power laser systems is still an extreme technological challenge. Typical solutions for fast switching up to the GHz level force a trade-off between speed and high-power capability. The novel approach presented herein bases on the coherent combination of at least two parallelly working amplifier channels that are coherently combined prior the CPA compressor. Coherent combination technology has been used so far as a power-scaling concept [3] allowing to increase average power and output energy of a laser system linearly with the number of combined channels. However, it also enables fast switching of the output port by changing the phase between the two interferometrically combined amplifier channels. The advantage of this approach is that the switching element (such as an fiber-coupled electro-optical modulator) can be integrated at an early low-power stage of the system, while it actually performs as an external modulator placed at the system output. However, at the output position, only a power-scalable beam combining element has to be employed.
关键词： kW average power levels,GHz-bursts,ultrafast external modulation,femtosecond fiber lasers
更新于2025-09-11 14:15:04
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[IEEE 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Munich, Germany (2019.6.23-2019.6.27)] 2019 Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC) - Passively Mode-Locked High-Repetition Rate Er:YLF Laser at 2.81 μm Generating 72 ps Pulses
摘要： The erbium-doped active media allow to generate laser radiation in spectral range 2.7-2.94 μm if the laser transition 4I11/2→4I13/2 is used. Since the laser radiation in this spectral range is strongly absorbed in the water these lasers can be used in medicine (surgery, ophthalmology, urology). Nowadays, there are many papers deal with erbium-doped bulk active media operating in free-running or Q-switched regime, nevertheless, the passively mode-locked lasers are mainly built with Er-doped fibres. However, the compact passively mode-locked erbium-doped bulk lasers could offer a higher repetition rate and smaller dimensions. To date, the shortest laser pulses (1.78 ns) generated with erbium bulk laser (Er:CaF2-SrF2) was obtained in Q-switched mode-locked regime. In this paper, the SESAM mode-locked compact Er:YLF laser with the picosecond pulses and GHz repetition rate for the first time, according to the author’s knowledge, is presented.
关键词： mode-locked,GHz repetition rate,picosecond pulses,laser,erbium-doped
更新于2025-09-11 14:15:04
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[IEEE 2019 21st International Conference on Transparent Optical Networks (ICTON) - Angers, France (2019.7.9-2019.7.13)] 2019 21st International Conference on Transparent Optical Networks (ICTON) - Materials for Nonlinear Optics in the GHz-THz Range
摘要： This talk starts with an outline of our hybrid approach combining Nonequilibrium Green's Functions with the Boltzmann equation for the nonlinear response of semiconductor superlattices. The nonlinearities are controllable and very good agreement has been found between theory and experiments. Next, we address the efficiency of the superlattices as frequency multipliers and their feasibility for room temperature THz radiation sources based on multiplication of GHz inputs.
关键词： semiconductor superlattices,THz,Boltzmann equations,GHz,nonequilibrium Green’s functions,frequency multiplication
更新于2025-09-11 14:15:04