基于MC1495的有效值音频数字功率计的设计

利用模拟乘法器MC1495实现负载电流与电压的乘积运算,经电平转换,滤波,由ICL7107完成A/D转换并驱动LED数码管,设计了有效值音频电功率计,实现对音频信号作用下负载有功功率的测量和数字显示,工作频率可从直流扩展到100kHz。电功率测量满度误差不超过±3%。可方便地作为一个独立单元插入到各类音频功率设备中。     

DTV发射机75 W射频功放模块的设计与实现

提出了一种用于数字电视发射机中的大功率射频功放模块的设计方案,采用平衡型放大器结构,以LDMOS器件作为功放管,给出了包括射频放大电路和直流馈电电路的实现方法,并提供了对系统增益及线性度等指标的仿真和测试结果.     

Energy-Efficient Optimization for Energy-Harvesting-Enabled mmWave-UAV Heterogeneous Networks

Energy Harvesting (EH) is a promising paradigm for 5G heterogeneous communication. EH-enabled Device-to-Device (D2D) communication can assist devices in overcoming the disadvantage of limited battery capacity and improving the Energy Efficiency (EE) by performing EH from ambient wireless signals. Although numerous research works have been conducted on EH-based D2D communication scenarios, the feature of EH-based D2D communication underlying Air-to-Ground (A2G) millimeter-Wave (mmWave) networks has not been fully studied. In this paper, we considered a scenario where multiple Unmanned Aerial Vehicles (UAVs) are deployed to provide energy for D2D Users (DUs) and data transmission for Cellular Users (CUs). We aimed to improve the network EE of EH-enabled D2D communications while reducing the time complexity of beam alignment for mmWave-enabled D2D Users (DUs). We considered a scenario where multiple EH-enabled DUs and CUs coexist, sharing the full mmWave frequency band and adopting high-directive beams for transmitting. To improve the network EE, we propose a joint beamwidth selection, power control, and EH time ratio optimization algorithm for DUs based on alternating optimization. We iteratively optimized one of the three variables, fixing the other two. During each iteration, we first used a game-theoretic approach to adjust the beamwidths of DUs to achieve the sub-optimal EE. Then, the problem with regard to power optimization was solved by the Dinkelbach method and Successive Convex Approximation (SCA). Finally, we performed the optimization of the EH time ratio using linear fractional programming to further increase the EE. By performing extensive simulation experiments, we validated the convergence and effectiveness of our algorithm. The results showed that our proposed algorithm outperformed the fixed beamwidth and fixed power strategy and could closely approach the performance of exhaustive search, particle swarm optimization, and the genetic algorithm, but with a much reduced time complexity.     

建设高品质通信电源系统

如何建设高品质通信电源系统,对于保证网络运行起到非常关键的作用。本文通过分析通信系统用电负载类别、负载对电源系统的要求及配制方式进行探讨,提出解决方案。     

3G底层核心实时状态检测模块的设计

本文首先提出了3G底层技术统一平台的概念,介绍了本平台及系统控制子系统的框架结构;然后给出了实时状态检测模块的功能和结构设计,包括其在整个系统中的位置、和其它功能模块的联系等;进而重点分析了该模块各个进程和任务的处理流程,并对它们是如何分工合作、实现对整个底层工作状态的实时性检测和控制等技术做了详细说明.     

单点相位式TOF深度探测器研究与设计

设计了一种单点相位式TOF深度探测器,并提出了相应的深度数据校正模型和消除数据抖动的方法,有一定的实用价值.国内外非常关注单点TOF相机芯片研究,广泛应用于手机、生物医疗、构建三维场景等领域.本文设计完成了数字模块设计并对顶层状态机及时序驱动信号进行寄存器巧妙配置,与模拟部分结合提高系统集成度.设计对深度测量的系统误差...     

用自积分式罗氏线圈测量纳秒级高压脉冲电流

介绍了测量纳秒级高压脉冲大电流信号用的自积分式罗氏线圈的优点、用途、基本原理及设计。利用传输理论分析了它的信号响应及干扰。对研制出的罗氏线圈进行了标定。设计的线圈的灵敏度在1.4mV/A,可以采用的上升时间小于2ns,脉宽小于200ns,电流信号10A～40kA。自积分式罗氏线圈广泛用于脉冲功率技术中的快过程大电流测量。     

同轴虚阴极振荡器实验研究

介绍了中国工程物理研究院应用电子学研究所关于同轴虚阴极振荡器实验的最新进展。实验结果表明,带阳极反射板结构的同轴虚阴极振荡器比不带阳极反射板结构的同轴虚阴极振荡器输出微波功率更高,频谱更纯。在二极管电压350 kV,电流23 kA条件下,输出微波峰值功率500 MW,能量转换效率约6.2%,工作频率为3.3 GHz。对实验结果进行了理论分析。     

Propagation characteristics of annular laser beams passing through the reflection Bragg grating with deformation

When high-power annular laser beams produced by the unstable resonator pass through the volume Bragg grating (VBG), absorption of light in the VBG will induce a temperature increment, resulting in changes in surface distortion. Considering that the surface distortion of the grating induces index and period differences, the scalar wave equations for the annular laser beams propagating in the VBG have been solved numerically and iteratively using finite-difference and sparse matrix methods. The variation in intensity distributions, the total power reflection coefficient, and the power in the bucket (PIB) for the annular laser beams passing through the reflection VBG with deformation have been analyzed quantitatively. It can be shown that the surface distortion of the VBG and the beam orders of the annular beams affect evidently the intensity distributions, the power reflection coefficient, and the PIB of the output beam. The peak intensity decreases as the deformation of the VBG increases. The total power reflection efficiency decreases significantly with the increase in deformations of the VBG. The PIB of the output beam decreases as the obscuration ratio β and the deformation of the VBG increase. For the given obscuration ratio β, the influence of deformation of reflection VBG on the PIB of the annular beams is more sensitive with increase in distortion of the VBG and decrease in beam order.     

基于Z箍缩装置的实验室天体物理研究

大型高功率脉冲装置广泛应用于高能量密度物理的实验室中,随着诊断技术和流体力学模拟技术水平的提高,基于此类装置,实验室天体物理方向取得一些新的重要进展,文章主要介绍帝国理工大学Z箍缩结构的MAGPIE 脉冲功率装置上开展的关于磁重联和喷流的实验进展,在磁重联实验中,发现重联电流片中电子温度和离子温度远高于入流等离子体的温度,必然有其他效应导致电子和离子的异常高温;喷流实验中观察到弓形激波和锥形激波的产生。最后对Z 箍缩装置实验室天体物理学的未来发展做一些展望。