A 6-bit 4 GS/s pseudo-thermometer segmented CMOS DAC

A 6-bit 4 GS/s, high-speed and power-efficient DAC for ultra-high-speed transceivers in 60 GHz band millimeter wave technology is presented. A novel pseudo-thermometer architecture is proposed to realize a good compromise between the fast conversion speed and the chip area. Symmetrical and compact floor planning and layout techniques including tree-like routing, cross-quading and common-centroid method are adopted to guarantee the chip is fully functional up to near-Nyquist frequency in a standard 0.18 #m CMOS process. Post simulation results corroborate the feasibility of the designed DAC, which can perform good static and dynamic linearity without calibration. DNL errors and INL errors can be controlled within 4-0.28 LSB and 4-0.26 LSB, respectively. SFDR at 4 GHz clock frequency for a 1.9 GHz near-Nyquist sinusoidal output signal is 40.83 dB and the power dissipation is less than 37 roW.     

基于分数阶滤波器的ADPCM预测误差信号处理

ADPCM音频压缩算法在G．721,G．723和G．726等相关数字语音通信协议中得到广泛应用。针对ADPCM中普遍存在的预测误差信号镜频干扰和高频噪声的问题,提出了基于分数阶积分器的误差信号频谱压缩滤波迭代算法和基于分数阶积分器的逆系统信号恢复迭代算法,为进一步提高音频压缩编码品质提供了新的方法,理论分析和仿真结果表明所提出方法的可行性。     

分数阶IIR和FIR滤波器及其逆系统的研究

分数阶滤波器( FrF)是传统整数阶滤波器的推广,在控制和信号处理等领域有广泛的应用前景.本文对离散时间FrF的一般表达形式进行了讨论；研究了基于Taylor级数展开的分数阶递归和非递归型IIR滤波器及其逆系统的结构和频率特性；分析了多项式近似情况下,递归和非递归型FIR FrF的频率特性与滤波器参数的关系；研究了非递...