Method and apparatus for time invariant pulse detection

Abstract

According to the present invention, a relatively straightforward, cost-effective technique for eliminating and/or reducing inaccuracies, such as amplitude induced timing errors, is provided in a pulse detection system without reducing bandwidth or degrading the signal-to-noise ratio. Exemplary embodiments detect a change in polarity of slope in a pulse of received energy to provide accurate pulse detection in the presence of noise, without degrading signal-to-noise ratio. Exemplary embodiments can create a time-invariant pulse from a single received, amplitude variant pulse, wherein a rising edge of the detected pulse is coincident with a change in a polarity of slope of the received pulse. Thus, a repetitive pulse signal is not needed to provide accurate pulse detection. Further, exemplary embodiments eliminate any need for complex circuitry since, for example, they are based on using cost-effective differentiators and do not require a reset signal to be asserted between pulses. In addition, exemplary embodiments do not strip the pulse-width information from the received signal, but rather can produce an output pulse which is proportional in width to the received pulse.