期刊文献+
共找到22篇文章
< 1 2 >
每页显示 20 50 100
音叉作为空间频率调制器可行性的研究
1
作者 程时琦 王崇真 +1 位作者 冯薇 张文碧 《云南工业大学学报》 1992年第Z1期127-132,共6页
本文对用音叉作为空间频率调制器的可行性进行了研究。我们尝试了用音叉作为一个简单的空间频率调制器,用时间平均全息干涉法测量了音叉的振幅,并测量了它的频率,用光电扫描法观测了其振动模式。得出结论:在扫描范围不大时,音叉可以作... 本文对用音叉作为空间频率调制器的可行性进行了研究。我们尝试了用音叉作为一个简单的空间频率调制器,用时间平均全息干涉法测量了音叉的振幅,并测量了它的频率,用光电扫描法观测了其振动模式。得出结论:在扫描范围不大时,音叉可以作为空间频率调制器。 展开更多
关键词 LAMBDA 系统 时间平均干涉测量 空间频率调制器 音叉
下载PDF
利用Doppler频率调制器和SF_6分子饱和吸收对CO_2激光稳频
2
作者 孙洁 周松波 《辽宁师范大学学报(自然科学版)》 CAS 2000年第1期51-53,共3页
讨论了利用多普勒频率调制器和气体饱合吸收效应对 CO2 激光的稳频装置 .
关键词 饱合吸收 稳频 二氧化碳激光 SF6 频率调制器
下载PDF
基于STM32微控制器的高频脉宽调制器的设计 被引量:4
3
作者 温亮 郭钟宁 +1 位作者 陈朝大 陈晓磊 《计算机测量与控制》 2018年第12期97-100,共4页
高频脉冲电源对提高微细电解加工的工艺性有着重要的作用,而脉宽调制器经驱动电路生成IGBT控制信号决定着高频高压脉冲电源的输出频率及占空比;针对电解加工工艺的特殊性,创新性地提出基于32位微型控制器芯片STM32F103RCT6为核心的调频... 高频脉冲电源对提高微细电解加工的工艺性有着重要的作用,而脉宽调制器经驱动电路生成IGBT控制信号决定着高频高压脉冲电源的输出频率及占空比;针对电解加工工艺的特殊性,创新性地提出基于32位微型控制器芯片STM32F103RCT6为核心的调频调占空比的方案;根据脉冲频率、占空比可调的要求,完成了脉宽调制器的软硬件设计,通过编译运行程序代码进行一系列的调频、调占空比实验并利用示波器采集两路输出的PWM波形;实验表明,自行研制的脉宽调制器能稳定地调节两路PWM控制信号的频率及占空比,验证了装置及设计的合理性。 展开更多
关键词 脉冲电源 微控制器 PWM控制芯片 频率调制器
下载PDF
具有数/模转换功能的DC-DC转换器
4
作者 纪宗南 《国外电子元器件》 2000年第10期23-25,共3页
MAX686是一种具有数/模控制功能的新颖DC -DC转换器 ,它具有转换精度高、体积小、集成度高、功耗小、效率高等特点。因此 ,在数控电源和单片机应用电路中获得广泛应用。
关键词 数/模转移器 DC-DC转换器 脉冲频率调制器
下载PDF
开关磁阻电机无位置传感器控制的研究 被引量:1
5
作者 郭传伟 殷天明 +1 位作者 王艳 张申君 《机车电传动》 2006年第1期26-29,共4页
概述了开关磁阻电机位置检测技术的研究现状,对现有的无位置传感器控制方法进行了综述,并且着重介绍了利用FM技术获得转子位置信号的方法,试验波形验证了该方法的可行性。
关键词 开关磁阻电机 无位置传感器 频率调制器
下载PDF
利用EAM和FM产生带宽3.8nm的光梳
6
作者 高迪 邵茜 +1 位作者 陈静远 李培丽 《光电工程》 CAS CSCD 北大核心 2015年第12期30-34,40,共6页
利用电吸收调制器(Electro-absorption Modulator,EAM)和频率调制器(Frequency Modulator,FM)的级联结构,提出了一种新型光学频率梳(Optical Frequency Comb,OFC)产生方案。本方案结构简单、易于控制,输出噪声低。对提出的方案原理进行... 利用电吸收调制器(Electro-absorption Modulator,EAM)和频率调制器(Frequency Modulator,FM)的级联结构,提出了一种新型光学频率梳(Optical Frequency Comb,OFC)产生方案。本方案结构简单、易于控制,输出噪声低。对提出的方案原理进行了理论分析,并利用Optisystem7.0软件进行仿真研究。仿真结果表明:产生了平坦的光学频率梳,其中心波长和谱线间距均可独立调谐。产生的OFC有效带宽为3.8 nm,得到了谱线间距为5 GHz的105条谱线。 展开更多
关键词 电吸收调制器 频率调制器 光学频率 带宽
下载PDF
A CMOS Power Amplifier with 100% and 18% Modulation Depth for Mobile RFID Readers
7
作者 高同强 张春 +1 位作者 池保勇 王志华 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第6期1044-1047,共4页
Aiming at the specific protocol of RFID technology,a 915MHz CMOS transmitter front-end for OOK modulation is implemented in a 0.18μm CMOS process. The transmitter incorporates a class-E power amplifier (PA), a modu... Aiming at the specific protocol of RFID technology,a 915MHz CMOS transmitter front-end for OOK modulation is implemented in a 0.18μm CMOS process. The transmitter incorporates a class-E power amplifier (PA), a modulator, and a control logic unit. The direct-conversion architecture minimizes the required on-and-off-chip components and provides a low-cost and efficient solution. A novel structure is proposed to provide the modulation depth of 100% and 18% ,respectively. The PA presents an output ldB power of 17.6dBm while maintaining a maximum PAE of 35.4%. 展开更多
关键词 CMOS power amplifier RFID TRANSMITTER modulation depth
下载PDF
适宜业余制作的立体声调频发射机
8
作者 曾武 《家庭电子》 2003年第9期23-24,共2页
本文介绍的立体声调频发射机电路原理如图1所示。射频检测器电路原理如图2所示。该发射机具有线路简单、性能稳定、制作调试容易、功率大、用途广泛等特点。因此,非常适宜广大业余电子爱好者及大中专、职高学生课余劳技制作。据实验,在+... 本文介绍的立体声调频发射机电路原理如图1所示。射频检测器电路原理如图2所示。该发射机具有线路简单、性能稳定、制作调试容易、功率大、用途广泛等特点。因此,非常适宜广大业余电子爱好者及大中专、职高学生课余劳技制作。据实验,在+11V直流电压供电时,该机发射功率约2W;在+14V电压供电时,其发射功率可达4W。 展开更多
关键词 立体声调频发射机 电路原理 制作方法 立体声频率调制器 射频功率放大器 射频功率指示电路
下载PDF
Analysis and Design of a ΔΣ Modulator for Fractional-N Frequency Synthesis
9
作者 张伟超 许俊 +1 位作者 郑增钰 任俊彦 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第1期41-46,共6页
This paper presents the design considerations and implementation of a novel topology digital multistage-noise-shaping (MASH) delta-sigma modulator suitable for fractional-N phase-locked-loop (PLL) frequency synthe... This paper presents the design considerations and implementation of a novel topology digital multistage-noise-shaping (MASH) delta-sigma modulator suitable for fractional-N phase-locked-loop (PLL) frequency synthesis. In an effort to reduce the complexity and dissipation,a pipeline technique has been used, and the proposed carry save tree (CST) algorithm optimizes the multi-input adder structure. The circuit has been verified through Matlab simulation, ASIC implementation, and FPGA experiment, which exhibits high performance and potential for a gigahertz range,low-power monolithic CMOS frequency synthesizer. 展开更多
关键词 △∑ modulator fractional-N frequency synthesis MASH architecture
下载PDF
A HIGH PERFORMANCE UWB LFM WAVEFORM GENERATOR 被引量:1
10
作者 Zhu Mingbo 《Journal of Electronics(China)》 2008年第6期774-779,共6页
In this paper, the design and implementation of a high performance Ultra-WideBand (UWB) Linear Frequency Modulation (LFM) waveform generator at Very High Frequency/Ultra High Frequency (VHF/UHF) band are introduced. F... In this paper, the design and implementation of a high performance Ultra-WideBand (UWB) Linear Frequency Modulation (LFM) waveform generator at Very High Frequency/Ultra High Frequency (VHF/UHF) band are introduced. Firstly, the design ideas for a high performance UWB LFM waveform generator are described. Then, a generation scheme for UWB LFM waveforms is presented according to the baseband digital generation method combining with the bandwidth ex-tension method via frequency doubling. An experimental system has been implemented and tested. The results show that the UWB LFM waveform generator achieves very high performance. 展开更多
关键词 Ultra-WideBand (UWB) Linear Frequency Modulation (LFM) Signal generation
下载PDF
Application of hybrid robust three-axis attitude control approach to overactuated spacecraft——A quaternion based model 被引量:2
11
作者 A.H.Mazinan 《Journal of Central South University》 SCIE EI CAS CSCD 2016年第7期1740-1753,共14页
A novel hybrid robust three-axis attitude control approach, namely HRTAC, is considered along with the well-known developments in the area of space systems, since there is a consensus among the related experts that th... A novel hybrid robust three-axis attitude control approach, namely HRTAC, is considered along with the well-known developments in the area of space systems, since there is a consensus among the related experts that the new insights may be taken into account as decision points to outperform the available materials. It is to note that the traditional control approaches may generally be upgraded, as long as a number of modifications are made with respect to state-of-the-art, in order to propose high-precision outcomes. Regarding the investigated issues, the robust sliding mode finite-time control approach is first designed to handle three-axis angular rates in the inner control loop, which consists of the pulse width pulse frequency modulations in line with the control allocation scheme and the system dynamics. The main subject to employ these modulations that is realizing in association with the control allocation scheme is to be able to handle a class of overactuated systems, in particular. The proportional derivative based linear quadratic regulator approach is then designed to handle three-axis rotational angles in the outer control loop, which consists of the system kinematics that is correspondingly concentrated to deal with the quaternion based model. The utilization of the linear and its nonlinear terms, simultaneously, are taken into real consideration as the research motivation, while the performance results are of the significance as the improved version in comparison with the recent investigated outcomes. Subsequently, there is a stability analysis to verify and guarantee the closed loop system performance in coping with the whole of nominal referenced commands. At the end, the effectiveness of the approach considered here is highlighted in line with a number of potential recent benchmarks. 展开更多
关键词 three-axis angular rates and rotations sliding mode finite-time control approach proportional derivative based linearquadratic regulator approach dynamics and kinematics of overactuated spacecraft
下载PDF
Research on CMOS Mm-Wave Circuits and Systems for Wireless Communications 被引量:2
12
作者 JIA Haikun CHI Baoyong +6 位作者 KUANG Lixue YU Xiaobao CHEN Lei ZHU Wei WEI Meng SONG Zheng WANG Zhihua 《China Communications》 SCIE CSCD 2015年第5期1-13,共13页
This paper lenges in the design of discusses some chal- millimeter-wave (mln- wave) circuits and systems for 5th generation (5G) wireless systems in CMOS process. The properties of some passive and active devices ... This paper lenges in the design of discusses some chal- millimeter-wave (mln- wave) circuits and systems for 5th generation (5G) wireless systems in CMOS process. The properties of some passive and active devices such as inductors, capacitors, transmission lines, translbrmers and transistors in mm-wave frequency band are discussed. Self-healing technique dealing with PVT variation, res- onant mode switching technique to enhance frequency tuning range of voltage controlled oscillator (VCO) and dual mode technique for power amplifier (PA) efficiency enhancement are introduced. At last, A fully-integrated 60 GHz 5 Gb/s QPSK transceiver with the transmit/receive (T/R) switch in 65nm CMOS process is introduced. The measured error vector magnitude (EVM) of the TX is -21.9 dB while the bit error rate (BER) of the RX with a -52 dBm sine-wave input is below 8e-7 when transmitting/receiving 5 Gb/s data. The transceiver is powered by 1.0 V and 1.2 V supply (except the phase-frequency detector and charge-pump in the frequency synthesizer which are powered by 2.5 V supply) and con- sumes 135 mW in TX mode and 176 mW in RX mode. 展开更多
关键词 CMOS MM-WAVE devices VCO PA sell-healing TRANSCEIVER
下载PDF
Magnetic sensitivity technology based on microwave modulation of solid state spin system NV center 被引量:1
13
作者 GAO Jian ZHAO Juan +4 位作者 MA Zong-min FU Yue-ping ZHANG Shao-wen LIN Zhao-dong SONG Jian 《Journal of Measurement Science and Instrumentation》 CAS CSCD 2018年第2期188-193,共6页
In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magne... In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magnetometer studied can reduce the frequency noise of system and improve the magnetic sensitivity by microwave frequency modulation.Firstly,ESR spectra by sweeping the microwave frequency was obtained.Further,the microwave frequency modulated was gained through the mixed high-frequency sinusoidal modulation signal generated by signal generator.In addition,the frequency through the lock-in amplifier was locked,and the signal which was proportional to the first derivative of the spectrum was obtained.The experimental results show that the sensitivity of magnetic field detection can reach 17.628 nT/Hz based on microwave frequency modulation technology.The method realizes high resolution and sensitivity for magnetic field detection. 展开更多
关键词 solid state spin system nitrogen vacancy(NV)center microwave frequency modulation magnetic sensitivity technology lock-in amplifier
下载PDF
Turbo-Coded Modulation of EVRC Speech Encoder with Unequal Error Protection for Fading Channels
14
作者 阿哈麦德 潘志文 +1 位作者 高西奇 尤肖虎 《Journal of Shanghai Jiaotong university(Science)》 EI 2003年第2期150-156,共7页
The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Persona... The Enhanced Variable Rate Codec (EVRC) is a standard for the Speech Service Option 3 for Wideband Spread Spectrum Digital System, which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigated the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power and bandwidth efficient coding scheme. The results show that the UEP system outperforms the Equal Error Protection (EEP) one by 1.45 dB at BER of 10 -5. 展开更多
关键词 enhanced variable rate codec (EVRC) turbo codes unequal error protection (UEP) quadrature amplitude modulation (QAM)
下载PDF
超宽带平坦多载波光源结构设计 被引量:3
15
作者 韩一石 郑俊文 +2 位作者 付晨远 赵蓓丝 陆敏婷 《光电子.激光》 EI CAS CSCD 北大核心 2019年第1期13-20,共8页
为了解决波分复用系统中传统光源稳定性差、成本高、带宽小等问题,本文提出了一种超宽带平坦光源发生器结构,该结构基于级联的电吸收调制器和两个频率调制器,得到了频率间隔相同且可调的高带宽、平坦度小的多载波光源。在单波长光信号... 为了解决波分复用系统中传统光源稳定性差、成本高、带宽小等问题,本文提出了一种超宽带平坦光源发生器结构,该结构基于级联的电吸收调制器和两个频率调制器,得到了频率间隔相同且可调的高带宽、平坦度小的多载波光源。在单波长光信号输入下,产生了大范围频率间隔可调平坦度小于0.2 dB的21个子载波的多载波光源,当驱动信号频率为8 GHz和9 GHz时,平坦度可达到0.07 dB;在多波长光信号输入下,得到了频率间隔为15 GHz,平坦度小于0.9 dB子载波数为275的超宽带平坦光源,频谱宽度可以达到THz以上。最后研究了10 GHz驱动信号下,电吸收调制器与频率调制器驱动信号的相位差、频率调制器的频率偏移以及电吸收调制器的啁啾因子对多载波光源的影响,结果表明,驱动信号的相位差在±10°上下波动时,平坦度最大改变了1.05 dB,频率调制器的频率偏移在±10 GHz范围内变化时,平坦度波动幅度仅为0.1 dB,表明该结构具有良好的稳定性和可控性。 展开更多
关键词 光通信 多载波光源 电吸收调制器 频率调制器
原文传递
射频识别卡的关键技术 被引量:2
16
作者 沈滨 《哈尔滨铁道科技》 2001年第2期13-14,共2页
介绍了射频识别卡在射频识别技术中的重要作用及工作原理、关键技术。
关键词 车号自动识别系统 射频识别卡 频率调制器 编码电路
原文传递
A polymer electro-optic modulator with ultra wide-band and low driving voltage 被引量:2
17
作者 Kambiz Abedi Habib Vahidi 《Optoelectronics Letters》 EI 2011年第6期423-426,共4页
In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element te... In this paper, a polymer electro-optic modulator is designed and simulated using the full vectorial finite element method. First order edge elements are used in finite element implementation, and the finite element technique is used to obtain modulator response thoroughly. From the numerical analysis, frequency dispersions of modulator's important parameters, such as microwave effective index nm , microwave characteristic impedance ZC and microwave loss a, are extracted. Our design exhibits electrical bandwidth of 260 GHz and drive voltage of about 2.8 V.cm in this frequency. 展开更多
关键词 电光调制器 低驱动电压 聚合物 矢量有限元方法 超宽带 频率调制器 有效折射率 调制响应
原文传递
Generation of ultra-wide and flat optical frequency comb based on electro-absorption modulator and frequency modulator 被引量:1
18
作者 高迪 李培丽 +1 位作者 邵茜 陈静远 《Optoelectronics Letters》 EI 2016年第2期97-100,共4页
An ultra-wide and flat optical frequency comb(OFC) generation scheme using multiple continuous wave(CW) light sources based on electro-absorption modulator(EAM) and frequency modulator(FM) is proposed. In the scheme, ... An ultra-wide and flat optical frequency comb(OFC) generation scheme using multiple continuous wave(CW) light sources based on electro-absorption modulator(EAM) and frequency modulator(FM) is proposed. In the scheme, each CW light source is broadened and modulated by the first EAM and FM, respectively. The second EAM is introduced to flatten the ultra-wide OFC lines. By setting the wavelength spacing of light sources equal to the bandwidth of sub-OFC, an ultra-wide OFC can be obtained. Principle analysis and simulation for the scheme are performed. The results show that in the case of a single light source, a tunable and flat OFC is obtained. With the increase of light sources, the bandwidth of the generated ultra-wide OFC expands rapidly. In the case of 28 light sources, a 22 GHz ultra-wide OFC with bandwidth of 16.52 THz can be generated. 展开更多
关键词 modulator bandwidth spacing tunable modulated flatness slightly oscillator continually seriously
原文传递
On-chip boost regulator with projected off- and on-time control
19
作者 Xiao-ru XU Meng-lian ZHAO Xiao-bo WU 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第8期1223-1230,共8页
The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(... The boost type power supplies are widely used in portable consumer electronics to step up the input voltage to adapt for the high voltage applications like light-emitting diode(LED) driving and liquid crystal display(LCD) biasing.In these applications,a regulator with small volume,fewer external components and high efficiency is highly desired.This paper proposes a projected off-and on-time boost control scheme,based on which a monolithic IC with an on-chip VDMOS with 0.2 Ω on-state resistance RDS-ON was implemented in 1.5 μm bipolar-CMOS-DMOS(BCD) process.A 12 V,0.3 A boost regulator prototype is presented as well.With projected off-time and modulated on-time in continuous conduction mode(CCM),a quasi fixed frequency,which is preferred for ripple control,is realized.With projected on-time and modulated off-time in discontinuous conduction mode(DCM),pulse frequency modulation(PFM) operation,which is beneficial to light load efficiency improvement,is achieved without extra control circuitry.Measurement results show that an efficiency of 3% higher than that of a conventional method under 0.5 W output is achieved while a step load transient response comparable to that of current mode control is maintained as well. 展开更多
关键词 Boost regulator Integrated circuits Pulse frequency modulation Projected off-time Projected on-time
原文传递
Graphdiyne as a saturable absorber for 2-µm all-solid-state Q-switched laser 被引量:1
20
作者 Yuqian Zu Jia Guo +4 位作者 Qianqian Hao Feng Zhang Cong Wang Jie Liu Bing Wang 《Science China Materials》 SCIE EI CSCD 2021年第3期683-690,共8页
As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a di... As a novel one-atom-thick carbon allotrope,graphdiyne(GDY)has attracted wide interest in two-dimensional materials owing to its unique feature with a planar layer comprising sp2-and sp-hybridized carbon atoms and a direct natural bandgap.A high-quality saturable absorber(SA)based on GDY was successfully fabricated,and the nonlinear saturable absorption properties were investigated.A compact diode-pumped solid-state passively Q-switched laser based on the as-prepared GDY-SA could be operated at 2µm.The Q-switched laser delivered a maximum average output power of 1.29 W at a central wavelength of 1908.41 nm with up to 54.8%slope efficiency.A repetition rate of 91.58 kHz and single pulse energy of 23.08µJ were obtained.This work is the first application of GDY as an SA to generate all-solid-state pulsed lasers.These results indicate that GDY is a promising SA for solid-state pulsed lasers and has further application potential for ultrafast photonic devices in the 2-µm region. 展开更多
关键词 graphdiyne saturable absorber all-solid-state laser passively Q-switched two-dimensional materials
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部