Design and Characterization of High Gain Amplifier for ELF Receiver Application

This paper deals with the design and characterization of high gain amplifier for extremely low frequency (ELF) receiver application. As the low level of ELF waves received by the antenna, an amplifier is considerably required to enhance receiver performance before data acquisition. The amplifier is built based on a low noise operational amplifier (Op-Amp) OP27 and intended to achieve high amplification in the frequency range of 1Hz to 50Hz. In order to avoid undesired frequency, the amplifier is equipped with the 2nd order low-pass active filter using the Sallen-Key topology with the cut-off frequency of 50Hz. The characterization results show that the proposed ELF receiver has maximum high gain of 60.8dB and high sensitivity for different low level inputs.