CMOS 5th Derivative Gaussian Impulse Generator For UWB Application

Abstract

A complete impulse generating system was designed and simulated which generates the fifth order derivative of the Gaussian pulse intended for use in an impulse-type ultra-wideband wireless communication system. By using a continuous-time FIR impulse shaping filter, the system transforms a normal Gaussian pulse signal obtained from an existing CMOS Gaussian pulse generator into its fifth derivative. The transformation filtering was accomplished without lengthening the time duration of the original pulse or causing any noticeable ringing effects. The final output waveform closely resembles the fifth derivative of the Gaussian pulse, and also satisfies the spectral mask emission requirements specified by the Federal Communications Commission (FCC). The impulse shaping filter within the system is a 15 tap, continuous-time finite impulse response (FIR) filter which can easily be realized in CMOS by employing commonly used system blocks, such as delay circuits and amplifiers.