An Analog Gabor Transform Using Sub-Threshold 180-nm CMOS Devices

The Gabor transform can be used to represent a signal in terms of a set of pseudo basis functions, allowing a signal to be split into parallel paths of a lower bandwidth. An analog Gabor transform using sub-threshold CMOS continuous time filters designed from time domain impulse responses is described. A novel method for designing low power gm-C filters using simple models of identical transconductors is used to specify the transistor sizes. Measured results show that the transform consumes 7 ??W for an input signal bandwidth of 4 kHz, making it suitable for ultra low power systems.