摘要
开关电流技术是一种新型的电流模式的模拟取样数据信号处理技术,对于实现小波变换具有很大的优势。Morlet小波在时域和频域都具有较好的局部性,能够提取信号中的幅值和相位信息。用开关电流技术实现Morlet小波变换的关键是高斯函数发生器。用Padé逼近获得高斯函数的有理分式逼近后,可以用开关电流一阶节和二阶节来实现高斯函数发生器。将高斯函数发生器与开关电流振荡器和乘法器级联后,通过调节时钟频率和输出电流镜晶体管的宽长比,即可实现不同尺度下的Morlet小波。将系统级电路在Cadence Spectre下仿真,使用SMIC0.18μm工艺,电源电压为1.8V,仿真结果显示了Morlet小波发生器的良好性能,表明了该方法的可行性。
Switched-current（SI） is a new current mode analog sampled data signal processing technology and it is suitable for wavelet transform.Morlet wavelet has good locality in time and frequency domain,and it could extract amplitude and phase information of the signal.Using SI technology to realize Morlet wavelet transform,Gussian function generator is the key.The rational fraction approximation of Gaussian function can be obtained by Padé approximation and implemented by SI first and second order section.Combining the Gaussian function with SI oscillator and multiplier,through adjusting the clock frequency and W/L ratio of output current mirror transistors,the Morlet wavelet at different scales can be realized.The system level circuit is simulated with Cadence Spectre,SMIC 0.18 μm,and the power supply voltage is 1.8 V.The simulation results show the Morlet wavelet generator is good and the method is feasible.
出处
《桂林电子科技大学学报》
2011年第4期280-283,共4页
Journal of Guilin University of Electronic Technology
基金
广西科学研究与技术开发计划项目(0731021)
