The Implementation Of Morlet Wavelet Transform Based On Switched Current Technology

This paper firstly introduced that wavelet transform is the latest time-frequency analysis tools. It can decomposes a signal into components that appears at different scales and tunes the time-frequency window automatically and has a strong flexibility. Switched-current technology as a new technology to process analog sample-data has a broad development prospects. As the substitute technology for switched-capacitor,the switched-current circuit is a new technology to process analog sample-data. The advantages of the switched-current circuit are its simplicity of implementation,potential for high speed,low-voltage operation and compatibility. It was a pioneering work at home and abroad using switched-current technology to implement continuous wavelet transform, and it had provided a new way for continuous wavelet transform.This paper introduced the method and principle of the implementation of wavelet transform in the time-domain and frequency-domain, and the modules of switched-current circuit in detail compared with switched-capacitor circuit. The paper designed a biquad second-order Butterworth filter based on switched-current integrator. The paper analyzed some error of switched-current circuit,which is of certain guidance and reference value to the compensation of switched-current circuit.This paper deeply studied the implementation method and principle of the wavelet transform in time-domain and frequency-domain. The amplitude modulation technology based on the time-domain is suitable for simple sine wavelet transform, so the application is limitied. In frequency-domain, switched-current integrators are used to synthesize Gaussian band pass filter by using leapfrog configuration to simulate passive ladder filter to implement the wavelet transform of Morlet. Taking Gaussian filter as the prototype, the paper design a leap-frog filter, and synthetic with switched-current bilinear integrator. This filter which is five order leap-frog filter was designed in the clock frequency of 8KHz, and the upper frequency is 1,000 rad /s , the lower frequency is 4,000 rad /s . It proved the feasibility by simulation using Pspice and Matlab.