Receiving Pre-processing Circuits Modular Design

Sonar equipments are necessary precision electronic instruments for ships and submarines.Signal pre-processing capabilities of sonar receivers have direct effect on the work performance of sonar equipment,the thesis includes two aspects:1. modular receiver design;2.isolated receiver modules design.Sonar equipments usually need many receivers,it wastes much time in the process of Circuit Production,it also effect system research and design progress.Many receivers in sonar system make the sonar equipments large,so it will decrease portability of equipments. To solve the above shortcomings,design Modular Receiver.To solve the interference of digital circuits on anlog circuits,design three kinds of circuits that analog circuits are isolated from digital circuits:1.analog voltage control gain;2.digital bits control gain;3.multiplexer control gain. Use electromagnetic compatibility rules to design the circuits,try to weak the interference on analog circuit.Compare the performance of three receivers,and do experiment on them,finally get the best way of receiver design.Experiments show: modular receiver and isolated receiver modules both work well,and get several kinds of low input noise receivers'design structures,finally use the advantages of modular receiver and isolated receiver to propose the receiver structures with low noise and high immunity...