The Development Of Fpga-Based Phased Signal Generator For P-HIFU System

Phased signal generator is one core components of P-HIFU system. In P-HIFU system, phased signal generator generates multi-channel square wave with specified phase under the controlling of input command. These square wave signal amplificated by the multiple resonant power amplifier then drive the sphere array of ultrasonic piezoelectric crystal to focus on specified position.According to theory of relationship between the phase accuracy and the parameters of heating focus, this paper analysised and identified the phased signal generator. Reference to the status phased signal generator in domestic and foreign, this paper discussed and defined the input control interface type, and selected FPGA-based technology solution to generate phased signal.This paper designed the architecture of FPGA firmware, and used VHDL language or IP core to implement the firmware coding. This paper used embedded MCU to deal with the serial interface communication, achieve the operation mode of―first download phase data and store, then output phased signal in order‖. This operation mode can implement the function of heating focus fast-moving.Adding IP core of PCI interface, the pahsed signal generator development by this can used an one PCI card that insert in the PCI slot, generating phased signal rapidly and implementing the fast-moving function―in real-time‖.This paper completed the hardware system design of phased signal generator, including selection of key chip, schematic design of circuit and PCB production. In this paper, additional hardware monitoring circuit improved the security of the phased signal generator. Meanwhile, the hardware design of this paper has improved the integration of phased signal generator and maked it easy to use.Finally, this paper alalysis and gives solution of key issues on accuracy of output signal. Through hardware and software debug and experimental testing, the phased signal generator developed by this paper make with the intended performance and functional requirements, and also has advantages of high security, high integration, easy to use.