Gamma- and electron-irradiation effects on second order active filters

Operation of second order active filters, based on operational amplifiers, on gamma- and electron-environments was studied. The response curves of low, high and band-pass filter circuits were plotted at different gamma and electron dose levels. From which the effects of radiation on the maximum gain, cutoff frequency, bandwidth and steepness factor of both Chebyshev and Butterworth filters were studied. The results show that low pass active filters, either Butterworth or Chebyshev, are insensitive to radiation exposure. On the other hand, the effect of radiation exposure of high pass filter was shown to improve their response characteristics. For band pass filters, their gain and bandwidth were shown to increase. The study was extended to include the radiation defects modification using the shelf and oven annealing techniques.