Design and Implement of Digital Modulator Based on Improved DDS Technology and DSP Builder

In this paper, according to the basic theory of digital modulator, the design model of digital modulator is built by using the improved Direct Digital Synthesizer (DDS) technology through running the Matlab/DSP Builder environment. Firstly,analyse the function of each module in this model and simulate the grade of algorithms to it and also produce VHDL language, then carry on Register Transport Level (RTL) grade simulation to the model in Modelsim. In the end, it also introduces the way to realize digital modulator in Field Programmable Gate Array (FPGA) chip, which verify the correctness and validity of the model. This design can not only produce many kinds of the digital signal modulation, but can also simplify the hardware circuit of the modern system greatly and save plenty of the system resources and improve the reliability and flexibility, what is more, compared with other designs, the performance price ratio of the design has advantage in modulated signal device and possess certain practicability and usefulness.