Design of Digital Costas Phase-locked Loop Based on FPGA
Kejie Li · Mini-micro Systems · 2005
Presented the designing method of digital Costas phase-locked loop(PLL) with EDA technology. Linear model was set up in continuous time domain and gives loop equation. Utilizing the relation of Laplace transform and Z transform, linear phase model of second order discrete time domain Costas loop circuits was deduced from phase continuous time domain model . The implementation method of discrete Costas loop was researched. Loop filter was discussed in discrete time domain. The discrete time domain implementation method of DCO was discussed. Logical circuit of the digital second order Costas loop was implemented in FPGA chip with VHDL. VHDL program was synthesized with synplify tool. The function of design was simulated with applied software tool modesim.