Design of switched-current wavelet filters using signal flow graph

A novel scheme for the design of switched-current (SI) wavelet filter is proposed. The signal flow graph (SFG) inverse follow-the-leader feedback (IFLF) structure is employed in the filter design. The presented approach is well suited for the wavelet transform since the SFG method can realize arbitrary rational function derived from any approximation technique, with relatively low sensitivity magnitude. Also, due to the characteristics of SI circuits, the dilation constant across different scales of the wavelet transform can be easily realized by controlling the sampling frequency, which facilitates the practical circuit design. The Gaussian wavelet is used as an example in this paper to elaborate design details.