提出了两种通用有源电流模式滤波器：1.用两个电流传送器（CCII）实现的电流模式三输入单输出二阶滤波器新电路,选择不同的输入信号组合即能获得低通、高通、带通、陷波和全通五种二阶滤波函数；2.由CCII和多输出端跨导运算放大器（OTA）实现的单输入多输出滤波器新电路。所提电路结构简单、中心频率ω0和品质因数Q独立可调、无源元件全部接地，滤波器特性参数对无源元件灵敏度低。理论分析和计算机仿真表明所提电路方案正确。

A fully differential R-MOSFET-C fourth-order Bessel active low-pass filter employing passive resistors and current-steering MOS transistors as a variable resistor is proposed. The implementation relies on the tunability of the current-steering MOS transistors operating in the triode region which counteract the deviation of resistors in integrated circuit manufacturing technology in order that the group delay of the Bessel active filter can be realized accurately. A 0.75 us group delay 520kHz frequency fourth-order Bessel lowpass filter based on a passive doubly terminated RLC prototype was designed and fabricated using 3.3V power supply and 0.35um CMOS technology. Chip test results demonstrate better than -65dB THD with @ 100kHz, 1.65-Vpp signal, frequency tuning range of more than ten decades from 0.6kHz to 550kHz, chip area of 0.32mm2 and power consumption of 13.3mW.

A systematic method for fault diagnosis of analogue circuits based on the combination of neural networks and wavelet transforms is presented. Using wavelet decomposition as a tool for removing noise from the sampled signals, optimal feature information is extracted by wavelet noise removal, multi-resolution decomposition, PCA (principal component analysis) and data normalisation. The features are applied to the proposed wavelet neural network and the fault patterns are classified. Diagnosis principles and procedures are described. The reliability of the method and comparison with other methods are shown by two active filter examples.

According to the principle of fault detect and diagnosis, this paper presents a new technology of data mining to deal. with a lot of data got from fault detection and diagnosis. A method using database technology to solve fault detection and diagnosis is developed.

本文提出了一种新的利用跨导运放OTA精确实现电压-电流型硬限幅函数神经元方法，它的主要特点是容易实现、且神经元的输出幅值可调。本文所提的基于OTA的硬限幅函数神经元（简称OHL）非常适合于求解L1问题的神经网络跨导模式综合实现。实例和计算机仿真结果与理论分析相吻合。