低功耗全集成微电子神经桥接电路的设计

神经传导束中断是脊髓损伤后功能障碍的主要原因。微电子神经桥是利用微电子芯片或模块旁路受损神经传导束,重建因神经通路中断而丧失的功能。设计了一种基于0.5μm CMOS工艺的低功耗、全集成微电子神经桥电路,版图面积为1.21 mm×1.18 mm。详细介绍了微电子神经桥核心单元电路低功耗两级运算放大器和输入/输出轨至轨运算放大器的设计。仿真结果表明,微电子神经桥接系统的通频带完全覆盖神经信号的频谱范围,增益可调至足够大,适用于神经信号探测和功能电激励。系统在±2.5 V供电情况下,功耗仅为3.4 mW,低功耗和系统全集成使得微电子神经桥向最终实现体内植入迈进了一步。     

双面显示技术的进展

近年来,双面显示技术成为国际上研究的热点课题之一.双面显示板是一种能够在显示器件两侧显示图像的器件,相较于传统的使用两块显示板相对放置的双面显示板,它以功耗低、体积小、成本低等优点,在各领域有广泛的应用前景.文章对双面显示技术的发展状况进行了综述,介绍了近年来逐渐应用于双面显示的LCD、OLED、PDP等几种主流双面显示技术.     

Weight Pick: an efficient packet selection algorithm for network coding based multicast retransmission in mobile communication networks

This paper proposes an efficient packet selection algorithm, called Weight Pick, for improving the efficiency of a network coding based multicast retransmission protocol in mobile communication networks. Unlike existing packet selection algorithms, Weight Pick introduces the concept of a dynamic combination number in performing network coding. Based on this concept, a base station dynamically determines the number of packets combined or encoded in a retransmission packet based on the current packet receiving status of users and the combination number for each retransmission packet can be different. In packet selection, Weight Pick attempts to find an encoding combination whose weight is not less than (C ? 1) for every user, where C is the combination number of that retransmission packet. Simulation results show that Weight Pick can significantly improve the retransmission performance as compared with existing packet selection algorithms in terms of both packet loss ratio and packet transmission delay.     

An Enhanced Link Adaptation Scheme Based on Cooperative Interference Prediction for MIMO-OFDM Systems

Dynamic inter-cell interference (ICI) causes channel quality indicator mismatch such that system throughput is reduced. In this paper, an enhanced link adaptation scheme based on cooperative interference prediction is proposed to reduce the mismatch. The scheme predicts the dynamic ICI within a cluster of base stations (BSs) for improving the link adaptation accuracy. With the dynamic ICI prediction, more accurate modulation and coding scheme can be selected without increasing the overhead over the air. System level simulations show that the proposed scheme significantly improves the system spectral efficiency (SE), especially the cell-edge SE.     

基于信念传播的分布式最大权匹配算法

针对目前已有的基于信念传播的分布式算法在处理一般图时会出现振荡与不确定现象,导致无法收敛或收敛至不正确解这些方面的不足,分析了其中的振荡现象并改进了相邻边交换消息的计算公式,以及对其中的不确定现象并提出了一种新的处理方法,以消除不确定性,从而形成了一种改进的基于信念传播的分布式最大权匹配算法。仿真结果表明,改进算法具有接近于最优解的良好性能。     

Wideband Frequency Synthesizer at X/Ku Band by Mixing and Phase Locking of Half Frequency Output of VCO

A wideband low phase noise frequency synthesizer at X/Ku band has been developed by using phase locking and mixing technique at half frequency of voltage controlled oscillator (VCO). The half frequency output signal of the VCO is down converted by a balanced mixer at C band to obtain an intermediate frequency (IF) signal used for phase locking of the VCO. An ultra low phase noise local signal source at 6 GHz is developed with a frequency multiplying chain driven by a 100 MHz oven controlled crystal oscillator (OCXO). Coupling circuit outside the VCO chip to the mixer does not need to be specially designed, which is beneficial to simplify the circuit scheme and improve the phase noise performance. Measurement results show that the phase noise of the output signal at 10.6 GHz to 11.8 GHz and 12.3 GHz to 13.0 GHz is better than −102 dBc/Hz at 10 kHz away form the carrier center. This frequency synthesizer can be used as local signal source or driving source for the development of wideband millimeter-wave frequency synthesizer systems.     

GPS模块射频输入端的阻抗控制

阻抗控制是PCB设计中的一个重要环节。良好的阻抗控制可以保证信号传输的质量,因此射频电路中阻抗控制必不可少。对影响传输线阻抗控制的主要因素进行了讨论,介绍了阻抗控制计算的一般方法,重点分析了如何利用ADS momentum软件对GPS模块射频输入端进行阻抗控制的设计。     

Investigation for Arcing Phenomenon in High Power MW/MMW Tubes

The arcing phenomenon in high voltage is one of the main failure modes for high power microwave and millimeter wave (MW/MMW) tubes. According operating principle of vacuum electronic devices, the factors of leading the arcing are discussed and the approaches for eliminating the arcing phenomenon are given in this paper. The theoretical and designing foundation raising the reliability for MW/MMW tubes are provided.     

MEMS湿度传感器信号采集与数字化处理研究

MEMS（微电子机械系统）湿度传感器是利用标准的CMOS技术加上MEMS的后处理技术制造,以其体积小、响应快等优点受到越来越多的重视,介绍了本实验室研制的MEMS压阻式湿度传感器的测试原理、硬件电路的设计和传输函数模型的建立,以及软件设计和封装设计,最后给出了样机的测试结果。     

射频MOSFET噪声模型研究

对0.13μm MOSFET噪声建模和参数提取技术进行了研究,在精确地提取了小信号模型参数之后,利用噪声相关矩阵技术从测量的散射参数和射频噪声参数直接提取了栅极感应噪声电流■、沟道噪声电流■和它们的相关系数,并用PRC模型中的参数来表示。将参数提取结果带入ADS中进行仿真,在2～8GHz频段上仿真结果与测量数据吻合良好。