Continuous Wavelet Transform Of The Analog Circuit

Since the Wavelet transform (WT) appearing in the middle of 1980's,it has been applied in the field of signal processing. But WT need heavy computations which were always competed by computer,it is impossible to deal with it in real-time . Continuous wavelet transform (CWT) is the strong tool to analysis the non-steady signals,also it's algorithm is more suitable for data compression than that of discrete wavelet transform (DWT). This thesis is organized around a very heat topic,i.e.,the performance of CWT implemented by analog circuits. The parallel versus cascade architecture has been discussed. Also discussed themethods on how to realize the CWT both in time-domain and frequency-domain and how to design the Gm - C bandpass filter used in realization of CWT. In order to optimize theperformance of Gm - C filter,linearization techniques are investigated and proposed. Due to process variation and parasitics,an automatic tuning is designed for center frequency /0 andquality factor Q Also,in this thesis,16-channel analogue CMOS CWT circuit has been realized.In the first chapter,the significance of WT is given. The reason why analog circuits is chosen to perform the CWT is also discussed. Some problems needed to be investigated and be involved are proposed.The history and category of WT is introduced in Chapter 2. The characteristics of WT and some basic wavelet are also given.The thesis introduces the techniques on how to computer the CWT and the architectures of VLSI which were used to perform the CWT in chapter 3. The Mellin rapid compute method is given. The analog or analog-digital mixed versus digital circuit used to perform WT has been discussed. Also discussed the methods on how to realize the CWT both in time-domain and frequency-domain. The problem needed to be investigated is proposed. Also bandpass filter of WT were designed.In the Chapter 4,the basic concept and characteristics about the current model circuit and transconductor (gm)are given. In order to optimize the performance of gmce\\,fourlinearization techniques and the design of consequently successful circuits are investigatedand proposed. At last,the four linearization techniques are summarizes .In the fifth chapter,the performance of transconductor-capacitor(Gm -C ) continuoustime filter is discussed. Due to process variation and parasitics,an automatic tuning is designed for center frequency and quality factor Q. Also,in this chapter,a two orderbandpass filter with tunable is designed. The effects on filter's performance of thenon-idealities of a CMOS OTA are studied and the computer simulations at the MOS transistor level are carried out.This thesis introduced the parallel and cascade architecture in chapter 6. A 16-channel filter bank is designed. It also present the result of this thesis according to the software of Matlab and Pspice .Chapter 7 summarizes all opinions and main conclusion in this thesis.