The design of the exclusive-or frequency multiplier circuit for the underwater acoustic signal

In order to make piezoelectric transducer for underwater acoustic detection work effectively, the driving signal is the key, which must have accurate frequency and 50% duty cycle, and frequency multiplication is a necessary operation. So it is very important to design the frequency multiplier circuit for the underwater acoustic signal. However, the resistance and capacitance components may reduce the accuracy of the conventional frequency multiplier circuit. In order to improve the design flexibility and accuracy, the principle of the exclusive-OR frequency multiplier circuit is presented here, and CPLD is employed to design exclusive-OR frequency multiplier circuit. The whole circuit includes three modules: operating frequency range selecting module, delay time measuring module and exclusive-OR frequency multiplier module. At the basic of the system simulation, the hardware experiments are done. The results show: the exclusive-OR frequency multiplier circuit implemented in CPLD is correct, and can stably output the 2^N (N<;4) multiplication frequency signal for the input square wave below 1 MHz.