Design of signal preprocessing circuit in receiver of buried cable detector

The scheme of multi-antenna array needs the system to have the ability of collection of multi-signal channels and can switch with requirement quickly. Also, it takes a high demand to the distinction of the circuit that the strong noise in complex environment will disturb the magnetic field easily. This article makes an optimal design to the signal preprocessing circuit, it takes resonance technology to improve the gather ability of special frequency, use difference amplifier to improve the common mode noise, and use band-pass filter to filter the noise. Gain control circuit is also used to adjust the signal level in order to make the signal to fit with the range of the A/D convertor.