Design Of Direct Digital Frequency Synthesizer Based On CORDIC Algorithm And Implementation

Direct digital frequency synthesizer (DDS) is the main tool of the modern frequency synthesis, it has high frequency resolution, continuously variable phase, rapid frequency conversion and many advantages. DDS is widely used in many fields. The main purpose of this thesis is to design a DDS with less hardware resource consumption and easy implementation.Firstly, the characteristics of the traditional DDS is analyzed. Then in order to reduce ROM consumption, a pipelined CORDIC algorithm is used to take the place of the ROM look-up table which is used in the traditional DDS.Secondly, the digital circuit part of the DDS is designed and implemented in FPGA, which includes the phase accumulator, the phase modulation adder, the phase-amplitude converter and the amplitude-modulation multiplier. And it also achieves amplitude modulation, phase modulation and frequency modulation.Finally, the module functions and system functions of the DDS are simulated and verified in Quartus II. And a comparison on hardware consumption between the traditional DDS system and the designed one is provided. The comparison shows that the CORDIC algorithm could help to reduce ROM consumption.Then a comparison about spectral output between the two are also provided in MATLAB. The comparison shows that the CORDIC algorithm could help to reduce the spurious spectrum of the system output.