Research And Manufacture Of Analog Hardware Circuit For Ultra-short Baseline Positioning System

The depths of the ocean are mysterious and unpredictable.The marine world contains kinds of resources that humans need.With the advancement of science and technology,humans have become more and more intensive in their exploration of the ocean.Underwater locating becomes one of the key research directions and has achieved rapid development in recent years.The research is to design,simulate and achieve the analog electronic part of the ultra-short baseline positioning system.The design includes preamplifier unit,receiver unit,transmitter unit and power supply unit.This paper has completed the design of the preamplifier unit with driving capability,and differentially amplifies the electric signal transformed by the receiver to improve the driving capability of the cable.Because the system is composed of 5 transducer elements,the receiver circuit is designed with 5 channels.The receiver's pre-amplifier is designed for low noise,and the two-stage voltage-controlled switch-resistance amplifier is used to make sure the gain is controllable.The transmitting unit uses the class D power amplifier and combines the design of a transformer to achieve power amplification of the signal.A dead time design is added to the logic circuit to prevent the MOS-FET from turning on at the same time.The matching circuit is designed according to the actual transducer.The power supply part uses a DC-DC power module with peripheral filter circuits to achieve the effect of isolated power supply and low power supply noise.Analysised and simulated the impact of the decoupling capacitors on the power supply side of the chip,and improvements have been made in the circuit.The main factors affecting the shielding effect of the chassis has been compared and simulated,it assisted the design of the chassis,and for the PCB layout,the design has been optimized.Finally,each unit circuit is debugged,the data is recorded,and the obtained data and results are analyzed.The results show that the designed circuit works stably and meets the design index requirements.