Design and Fabrication of a Semi-Gaussian Pulse Shaper using Approximation of Filter Functions with Linear Phase Characteristics

A seim-gaussian pulse shaper consisting of a differentiator(high-pass filter) and integrator(low-pass filter) has been developed using approximation of filter function with linear phase characteristics. The differentiator, which consists of a capacitor and a resistor, has been designed with pole-zero cancellation to prevent undershoot. And the integrator has been designed using a multi-feedback filter and Sallen-Key filter topology. Considering the peaking time and FWHM of the shaped pulse, the poles of filter’s transfer function were selected and verified using impulse response. The semi-gaussian pulse shaper produces a peaking time of 2.4 ㎲, a peak voltage of 2.5 V and a FWHM of 2.4 ㎲, which were very similar to an ideal gaussian pulse. Also the semi-gaussian pulse shaper shows a band-pass filter characteristics with a 3 dB bandwidth of 200 kHz and linear phase characteristics in the frequency range exceeding the bandwidth.