Study on low noise Semi-Airborne electromagnetic receiving amplifier circuit

Semi-Airborne Electromagnetic Method(SAME) is widely used in resource exploration because of its characteristics of strong adaptability to complex terrain, low detection cost and high efficiency. However, because the detection environment is extremely harsh and complex, the signal is often affected by environmental noise when passing through the amplifier circuit. Common low noise amplifier circuit is radio frequency amplifier, In order to meet the requirements of the bandwidth of the electromagnetic receiving system in the frequency domain of ground and air in 0.1Hz-10khz, this paper uses matching transistors to design a very low noise signal amplifier circuit and conducts circuit analysis. At the same time, the amplifier circuit is equipped with a power filter circuit, a bias circuit, and a low-pass filter circuit, which together constitute a signal conditioning circuit. The circuit is applied to the receiver ,which can effectively reduce the noise power density of the system and improve the Signal to Noise Ratio(SNR) of the system, thus improving the accuracy of the receiver.