High Sensitivity Very Low Frequency Receiver for Earthquake Data Acquisition
Abstract: A high sensitivity
very low frequency (VLF) receiver is developed based on AD744 monolithic operational
amplifier (Op-Amp) for earthquake data acquisition. In research related natural
phenomenasuch as atmospheric noise, lightning and earthquake, a VLF receiver
particularly with high sensitivity isutterly required due to the low power of
VLF wave signals received by the antenna. The developed receiver is intended to
have high sensitivity reception for the signals in frequency range of 10-30kHz allocated
for earthquake observation. The VLF receiver which is portably designed is also
equipped withan output port connectable to the soundcard of personal computer
for further data acquisition. Afterobtaining the optimum design, the hardware
realization is implemented on a printed circuit board (PCB) for experimental
characterization. It shows that the sensitivity of realized VLF receiver is
almost linear in the predefined frequency range for the input signals lower
than -12dBm and to be quadratic for the higher level input signals.
Author: Achmad Munir
Journal Code: jptkomputergg170076
