Switching current technology-based analog continuous wavelet transform circuit

Abstract

The invention discloses a switching current technology-based analog continuous wavelet transform circuit, which comprises a filter bank composed of switching current wavelet filters of which the impulse response is a basic wavelet approximating function and an extension function thereof, and a programmable clock signal generator circuit connected with the switching current wavelet filters; the number of the switching current wavelet filters in the filter bank is at least two; the switching current wavelet filters respectively correspond to different scales; switching current circuits of the switching current wavelet filters are composed of switching current integrator-based primary and secondary node circuits connected in series; and the scale change in the continuous wavelet transform is adjusted by a clock signal frequency output by the programmable clock signal generator circuit. The continuous wavelet transform circuit can process input signals in real time, is fully compatible with the digital CMOS VLSI process, is easy to integrate, and is suitable for low-voltage, low power-consumption, high-speed portable equipment and a high-speed signal processing circuit.

Description

technical field [0001] The invention relates to an analog continuous wavelet transform circuit, in particular to an analog continuous wavelet transform circuit based on switch current technology. Background technique [0002] Wavelet transform is widely used in signal processing, image processing, speech processing and many nonlinear scientific fields because of its good time-frequency local characteristics. The traditional wavelet transform needs to be completed by computer or digital signal processor, which has a large amount of calculation and poor real-time performance, and the processing process of this method needs to use A / D and D / A to convert between analog and digital signals, which is easy to generate signal Delay and waveform distortion, and the frequency range of the signal processed by this method is narrow, and it is difficult to reach the high frequency field. [0003] At present, in terms of the realization of wavelet transform circuits, there are many reali...

AI Technical Summary

Problems solved by technology

In the realization of the continuous wavelet transform circuit, the most representative one is the continuous wavelet transform based on the switched capacitor technology. This method realizes the control of the filter expansion coefficient by adjusting the clock frequency or the capacitance ratio, but the switched capacitor circuit requires high-quality linear capacitors. , is incompatible with the digital very large scale integration (VLSI) process, and it is difficult to realize mixed-signal circuits. At the same time, due to the reduction in the size of the integrated process, the power supply voltage is reduced, which will directly reduce the maximum voltage swing adapted to the switched capacitor, thus Reduce the maximum dynamic range of the circuit

Later, the continuous wavelet transform circuit based on the current mode appeared. Among them, some scholars used the Padé method to approximate the wavelet frequency domain transfer function, and used the bipolar transistor logarithmic domain circuit and the switching current circuit to realize the

Images