中图分类号： TN763.3
文献标识码： A
DOI：10.16157/j.issn.0258-7998.200377
中文引用格式： 董淑豪，吴东岷. 基于FPGA的高精度鉴相器实现[J].电子技术应用，2020，46(10)：57-60，78.
英文引用格式： Dong Shuhao，Wu Dongmin. Realization of high precision phase detector based on FPGA[J]. Application of Electronic Technique，2020，46(10)：57-60，78.

Realization of high precision phase detector based on FPGA

Abstract： Although the response speed of the phase detector based on analog circuit is fast, it is difficult to achieve high precision, and the development cycle is long and difficult to optimize. In order to detect the tiny phase change of micro-electro-mechanical system(MEMS) devices in real time, a high-precision phase detector based on field programmable gate array(FPGA) is proposed. The phase detector is mainly composed of digital mixer, finite impulse response(FIR) digital filter, direct digital synthesis(DDS) signal generator and analog digital converter conversion circuit. The phase detection method is to mix the measured signal with the reference signal with the same frequency, adjustable phase and initial phase of 90°, and extract the phase related difference frequency signal through high-order FIR filter, adjust the reference signal phase to make the difference frequency signal close to 0, then the phase adjustment amount of the reference signal is the phase of the measured signal. The clock frequency of the phase detector is 100 MHz, and the phase accuracy can reach 0.000 1°. The working frequency is flexible and adjustable. When it is used in PLL, it can be easily compatible with the driving circuit of MEMS devices.

Key words : FPGA；FIR；phase detector；DDS；MEMS