共查询到20条相似文献,搜索用时 15 毫秒
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Hassan Khalesi Abdolreza Nabavi Sattar Mirzakouchaki 《IEEJ Transactions on Electrical and Electronic Engineering》2015,10(2):144-148
A very low complexity impulse radio‐ultrawideband (IR‐UWB) transmitter suitable for balanced antenna is presented. This all‐digital transmitter employs the binary phase‐shift keying (BPSK) modulation scheme and eliminates the need for a balun. Also, a new Gaussian monocycle pulse generator is proposed which is used as impulse transmitted signal. The transmitter circuit was designed in 0.18‐μm complementary metal–oxide–semiconductor technology. The post‐simulation results show that the core chip size was only 0.02 mm2. The output amplitude pulse yielded 150 mV peak‐to‐peak under a supply voltage of 1.8 V. Simulation results show that the transmitter consumes 8.5 pJ/pulse for 200‐MHz pulse repeating frequency. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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超高频法是目前电力设备局部放电在线监测广泛使用的监测方法,超高频电磁信号的定量、定位研究需要稳定可靠的UHF信号模拟发生装置,针对这一现实需求,文章设计了一种基于数字电路的纳秒级脉冲源,用于产生PD UHF模拟信号。文章详细分析了利用数字电路产生陡脉冲的原理,选用简单的高速逻辑器件构建了脉冲发生电路,并采用虚拟仪器产生频率可变的方波信号作为脉冲源的触发信号。用Pspice仿真分析了门电路的脉冲响应特性,并搭建了试验电路进行性能测试。实验结果表明,该脉冲源产生的陡脉冲信号幅值可达2 V,脉冲重复率为50 k Hz-20 MHz,上升陡度为1 ns,脉宽为3 ns,能有效模拟PD UHF信号,并进行相关的局部放电实验。 相似文献
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Ahmed M. El‐Gabaly Carlos E. Saavedra 《International Journal of Circuit Theory and Applications》2013,41(2):150-167
A new energy‐efficient tunable pulse generator is presented in this paper using 0.13‐µm CMOS technology for short‐range high‐data‐rate 3.1–10.6 GHz ultra‐wideband applications. A ring oscillator consisting of current‐starved CMOS inverters is quickly switched on and off for the duration of the pulse, and the amplitude envelope is shaped with a variable passive CMOS attenuator. The variable passive attenuator is controlled using an impulse that is created by a low‐power glitch generator (CMOS NOR gate). The glitch generator combines the falling edge of the clock and its delayed inverse, allowing the duration of the impulse to be changed over a wide range (500–900 ps) by varying the delay between the edges. The pulses generated with this technique can provide a sharp frequency roll off with high out‐of‐band rejection to help meet the Federal Communications Commission mask. The entire circuit operates in switched mode with a low average power consumption of less than 3.8 mW at 910 MHz pulse repetition frequency or below 4.2 pJ of energy per pulse. It occupies a total area of 725 × 600 µm2 including bonding pads and decoupling capacitors, and the active circuit area is only 360 × 200 µm2. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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This paper proposes a maximum output power control system for variable‐speed small wind generators. The proposed control system adjusts the rotational speed of a single‐phase AC generator to the optimum rotational speed, which yields the maximum output power according to the natural wind speed. Since this adjustment is performed on‐line in order to adapt to variations in wind speed, the rotational speed of the single‐phase AC generator is adjusted by controlling the generated current flowing in an FET (field‐effect transistor) device, serving as the generated power brake, which is linked directly to the single‐phase AC generator. In order to reduce heat loss from the FET device, a PWM (pulse width modulation) controller is introduced. An experimental model of the proposed control system was built and tested, and the validity and practicality of the proposed control system were confirmed by the experimental results. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(1): 9–17, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20692 相似文献
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提出了一种产生正弦脉宽调制波的新方法。介绍了采用级数混合运算产生数字化正弦波数据的基本原理,不需要专门的ROM存储器,利用传统查表法就能够得到所需要的SPWM信号。基于所提出的方法设计了一种通用型SPWM波形发生器,利用FPGA内部的RAM资源例化成所需要的虚拟ROM存储器,用来存储由级数混合运算得到的1/4周期数字化正弦波数据,然后利用中心对称和轴对称运算得到整周期的正弦波,与三角形载波进行比较后输出SPWM信号。实验结果表明,该SPWM发生器具有可靠性高,电路结构简单,使用灵活等特点。采用所提出的方法设计的SPWM光伏逆变器已投入应用,性能良好,工作稳定。 相似文献
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静电放电小空间测试装置性能分析与验证实验 总被引:1,自引:0,他引:1
为了满足核辐射条件下静电放电(ESD)瞬态脉冲场小空间测试的需要,基于有源电光调制法研制了一种经济实用的传感器,并利用该传感器搭建了光纤传输式瞬态电场测试装置。在介绍传感器设计与研制过程的基础上,对测试装置的电性能进行了实验研究。通过频域信号注入实验、方波脉冲注入实验及方波脉冲辐照实验,对测试装置的响应时间以及线性度等指标进行了性能分析;通过ESD脉冲辐照实验,对测试装置性能进行了综合验证。实验结果表明,该测试装置的响应时间〈1ns,可用于ns级辐射场测试;其线性度良好,通过调整天线负载电容的取值可以调节测试灵敏度。该测试装置可用于静电放电辐射场的时域测试,能够在小空间测试静电放电瞬态脉冲场。 相似文献
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在超宽带雷达系统中,混沌脉冲位置调制(CPPM)信号通常是由时间间隔按混沌变化的高斯脉冲序列组成,针对高斯脉冲的天线辐射效率低的问题,设计一种调制脉冲为单周期脉冲的超宽带CPPM信号源。首先数字仿真验证了Tent映射作为调制函数的可行性,然后利用FPGA模块和以阶跃恢复二极管(SRD)为核心的模拟电路模块获得了主脉冲宽度为590 ps、主峰峰值为-1. 76 V且波形良好的单周期脉冲。自相关运算结果表明该信号具有良好的抗干扰能力和较高的检测概率;频谱图表明该信号没有直流成分,并且在低频区有极少的能量,作为雷达的发射信号时,可有效提高雷达天线的辐射效率。 相似文献
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Jun Kikuchi Koichi Igarashi Shinji Ibuka Shozo Ishii 《Electrical Engineering in Japan》2012,180(2):17-23
To analyze atmospheric‐pressure transient glow microdischarges powered by a fast high‐voltage pulse train generated by a nonlinear transmission line generator, we conducted a simulation experiment using double rectangular pulsed voltages having variable pulse intervals. The discharges were characterized by optical emission spectro‐scopy. Although the temporal evolution of the spectral line intensities of nitrogen molecules and ions followed the discharge current, the atomic helium line intensity did not follow the current. The development of a discharge at the interface between a helium gas flow column and the surrounding air affects the observed evolution of the spectral lines. The strong effect of metastable helium was confirmed. © 2012 Wiley Periodicals, Inc. Electr Eng Jpn, 180(2): 17–23, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21223 相似文献
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脉冲超宽带信号的单脉冲形式能够影响到传输信号的功率谱密度,单脉冲形式的选择应遵循频谱利用率高,抑制干扰灵活,脉冲产生容易等原则。对于信息数据的调制主要有基于幅度的调制(PAM )和基于时延相位的调制(PPM),主要的多址技术有跳时(TH)扩频调制、直接序列(DS)扩频调制,最主要的两种基本调制方式是 TH‐PPM 和DS‐PAM。采用高斯脉冲,将脉冲波形调制,跳时技术,直接扩频技术组合在一起,组成一种新的组合调制方式DS‐T H‐PSM调制,使一种信号具有3个属性,降低了信号捕获时判决的难度,增加了系统的安全性。 相似文献
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在提出脉冲提取思想的基础上,利用局部放电信号所固有的奇异性特征,将小波变换的奇异性检测原理应用于提取局部放电脉冲。为了满足局部放电在线监测的在线准实时要求,提出了改进的尺度空间滤波算法,并将其应用于局部放电脉冲的提取。通过相邻尺度的小波系数直接相乘,可以突出奇异点的信号,并获得基于尺度的屏蔽滤波器,将阈值方法和尺度空间滤波相结合,最终得到基于时域的屏蔽滤波器,将时域滤波器和原信号相乘,就可以提取出局部放电脉冲。仿真试验和发电机实测信号的算例表明,相对于模极大值算法,该方法在提高运算速度的基础上,不但能准确检测出局部放电脉冲,而且能很好地保持局部放电脉冲的幅度和位置。 相似文献
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Bon Ju Gu Wang Hoon Lee Kazuaki Sawada Makoto Ishida 《IEEJ Transactions on Electrical and Electronic Engineering》2012,7(3):337-341
This paper presents a low‐power radio frequency (RF) transmitter using dual‐pulse position modulation (DPPM) for a smart micro‐sensing chip (SMSC) with sensors and large scale integrated circuit (LSI) on the same chip. The DPPM method is presented by a fixed pulse and a variable pulse within the same time frame. The distance between the fixed pulse and the variable pulse describes the amplitude of the input signal. A modulator and a ring oscillator were designed for the RF transmitter using the DPPM method. In the modulator, the pulse width modulation (PWM) signal is generated by the intersective method, and narrow pulses are extracted at the rising and falling positions of the generated PWM signal. The designed oscillator has the function of an oscillation controller. The RF transmitter was fabricated with sensors for an SMSC by complementary metal–oxide–semiconductor (CMOS) technology. The power consumption of the fabricated modulator was 4.5 mW. The power consumption of the proposed RF transmitter was measured as 7.0–7.3 mW at an input signal of 0.8–2.5 V. The RF transmitter using the DPPM method was able to reduce the power consumption by a maximum of 50.3% compared to a transmitter using the PWM method, because in the latter the dissipated power was 8.4–14.5 mW at the same input signal. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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Yu Yu Yang Liu Wen‐jun Lu Hong‐bo Zhu 《IEEJ Transactions on Electrical and Electronic Engineering》2015,10(Z1):S7-S13
A novel measurement‐based antenna‐height‐dependent statistical root‐mean‐square (RMS) delay spread model under indoor stair environment is proposed. In this model, the RMS delay spread is described as a log‐normal random variable with antenna‐height‐dependent parameters in both line‐of‐sight (LOS) and the non‐LOS (NLOS) areas. The environmental independence of the RMS delay spread distribution is shown first. Then, the parameters of the proposed model are extracted using least‐squares and maximum likelihood estimation. The accuracy of the proposed model is verified by the extensive measured data, and the mean values of the RMS delay spread are compared with those in other related works. Finally, the interdependence of RMS delay spread and the coherence bandwidth is investigated. The proposed model can be applied to the physical layer designs of small cells in future 5G and ubiquitous mobile communication systems. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献
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A novel low power and high speed double edge explicit pulse triggered level converter flip‐flop 下载免费PDF全文
Ramin Razmdideh Mohsen Saneei 《International Journal of Circuit Theory and Applications》2015,43(4):516-523
One of the effective ways to reduce power consumption is using clustered voltage scaling technique. The level converter flip‐flop is needed to control static current when the block with Low Supply Voltage (VDDL) drives the block with High Supply Voltage (VDDH). One of the big challenges of design is that level converter flip‐flop has low power and high speed. In this paper, pulse triggered level converter flip‐flop and double edge pulse generator were proposed. This level converter flip‐flop used conditional data mapping technique for reducing power consumption. An explicit double edge pulse generator could be shared among several level converter flip‐flops so that power consumption would be reduced. Also, the number of stack transistor was reduced in the discharging path that causes delay decrease. The simulation results showed that the proposed flip‐flop reduced 20% of power consumption and 17% of delay in comparison with other flip‐flops at 50% data switching activity. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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作为高压高重复频率脉冲电压发生器的开关器件,磁开关的耐压、通流能力以及寿命远高于半导体开关,因而适用作为介质阻挡放电(DBD)激励电源的开关。为研究双极性高频下DBD等离子体放电特性,提出高频双极性磁脉冲压缩系统。首先,阐释通过全桥逆变电路、脉冲变压器和磁开关产生双极性脉冲的原理,并叙述该系统关键器件的设计;其次,利用PSpice仿真软件研究电路关键参数对输出波形的影响规律,测试电阻性负载电压波形,并与仿真结果进行对比分析。测试结果表明,通过双极性磁脉冲压缩系统,能够在负载两端输出的纳秒脉冲电压具有以下参数:幅值在5~13k V可调,上升沿100ns左右,重复频率可高至几千Hz。最后,针对高频双极性下的放电现象进行研究,结合DBD放电模型和放电图片探索高频双极性脉冲电压下放电特性与频率的关系,充实了高频放电理论研究。 相似文献
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Renxiang Zhu Lenan Wu 《International Journal of Adaptive Control and Signal Processing》2014,28(1):96-106
Nonlinear equalisers based on minimum BER are proposed for the equalisation of nonlinear time‐varying channels. To train the equalisers online, a sliding‐window‐based hybrid quasi‐Newton algorithm is proposed. Switching between sliding‐window stochastic gradient algorithm and sliding‐window quasi‐Newton algorithm makes the new algorithm significantly stabler with a fast convergence rate. Results from extensive simulation tests show that performance of nonlinear equalisers based on minimum BER is better than the equaliser based on minimum mean square error. The proposed algorithm demonstrates high efficiency as well. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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为合理评估变频电机绕组的绝缘性能,IEC建议采用脉冲方波电压开展测试并且选择合适的脉冲参数以减小电压波形带来的测试偏差。通过对脉冲电源波形参数选择的分析,研制了一台基于桥式固态开关器件的直接输出式脉冲方波电源,给出了脉冲变换主回路暂态参数的设计方法。波形测试结果表明该脉冲方波电源能够输出具有对称脉冲边沿特性的脉冲方波,通过控制半导体固态开关和调节充放电参数能得到最短脉冲边沿时间20 ns、最大重复频率20 kHz、最高电压幅值10 kV的对称脉冲波形,耐电晕寿命测试结果与相关研究结论一致。该脉冲电源运行可靠、结构简单,输出波形稳定,可用于开展脉冲电压条件下变频电机绝缘性能评估工作。 相似文献
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Sirichai Tammaruckwattana Kazuhiro Ohyama Shinji Arinaga 《IEEJ Transactions on Electrical and Electronic Engineering》2015,10(Z1):S96-S107
This paper proposes a wind turbine emulator (WTE) based on the blade momentum theory, and tests the variable‐speed wind power generation system using a pulse‐width modulation (PWM) converter to verify the accuracy of the emulator. The behavior of the wind turbine for natural wind is reproduced by the WTE based on the proposed theory. The variable‐speed wind power generation system employs a vector control system to control the torque and speed of the permanent magnet synchronous generator in the converter side. The windmill rotational speed is controlled to maximize the efficiency of the wind turbine against wind velocity. And the active power and reactive power are controlled in the inverter side, and the generated power is sent to the grid while controlling the DC link voltage to be constant at the same time. The behaviors of the WTE are compared with the simulation results and experimental results using a real wind turbine. These experimental and simulation results show that the test bench with the proposed WTE has sufficient performance and accuracy to verify variable‐speed wind generator systems. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. 相似文献