Water Ultrasonic Receiver Automatic Gain And Signal Processing Technology

Rocket depth charge is traditional and efficient weapon for attacking submarine, especially in offing. On the background of the new rocket depth charge multifunction fuze, the signal processing circuit of ultrasonic detection receiver is studied. The aim of this dissertation is to improve the performance of the receiver.Firstly the theory of the ultrasonic proximity module in new fuze is analysed. The factors which affect performance of the proximity fuze are studied. Especially, the technology of Automatic Gain Control and signal processing are studied which are key factors working on the performance of the receiver.Based on analyzing the theory of automatic Gain Control, operational amplifiers 0P37 and logarithmic D/Aconverter AD7111A are used to design variable gain amplifiers which can be controlled numerally, A/D convector LTC1405 is Used to test the echo, Complex Programmable Logic device is used for controller, and an arithmetic is designed for automatic Gain Control which is simulated and analyzed in order to test its feasibility.Basedon studying the theory of mixer, a digital mixer is designed with Complex Programmable Logic device. After studying thefilter, filter building blocks LTC1068 is taken to design the filter which has good selectivity. It is good for the receiver to detect the echo.The design of signal processing circuit in this paper can achieve anticipative purpose in the ultrasonic detection receiver of the new rocket depth charge multifunction fuze and it offers definite reference value to farther research of ultrasonic proximity fuze.