Based On Of The Dds Ramark Road Waveform Generated Design And Implementation

This paper introduces the principles of PLL,DDS and Quadrature modulation, compares the differences and similarities between direct digital waveform synthesizer(DDWS) and direct digital frequency synthesizer (DDFS), and analyses the basic theory of producing Linear Modulate Frequency( LFM) signal with DDS technology.At present the output frequency of LFM signal produced by digital technology can not meet the system's requirement , because of the limited speed of digital devices. To solve the problem, We can use DDS to get The Linear Modulate Frequency in midband ,utilize the PLL to produce The steady carrier frequency and clock reference, then realize the spectrum moved to X band by the combining of orthogonal modulator and mixing technology.This project implements the design of waveform generator in radar system, using the previous mentioned method. The principal technology performace of project are demonstrated in this paper,and the circuit design and test result are given. The test results indicate that the performance of output meet or exceed system requests. It works well in the radar system. In this paper many experiences in the testing process are summarized. The success of this project is of great importance for the development of the radar specialty in our research institute.