Abstract: A simulated signal source system is designed for the Global Position System (GPS) based on the Field Programmable Gate Array (FPGA). FPGA, a widely used programmable chip, is employed for the design of simulated signal sources. In this work the high-resolution and stable GPS satellite signal is generated by using FPGA cooperated with a Radio Frequency (RF) module. The application results show that our design can facilitate the realization of the control of multiple frequencies and hence substantially reduce the multi-frequency exploration period and risk.