Study On Wide-Band High-Resolution Frequency Synthesizer

Modern frequency source (frequency synthesizer)can generate thousands of the same stable and accurate frequencies from a high stable and accurate standard frequency. It is mainly applied in communication, radar, navigation, TV, electron reconnaissance, interference, spaceflight, remote control, instruments and meters. The design of frequency synthesizer will influence performance of electronic system directly, so it is called "heart" of electronic system, and it is one of important researches of electronic system.Specifications of frequency synthesizer includes: frequency scope, frequency stepping, frequency stability, phase noise, output power, spur suppression, time of frequency transformation, etc. because of different usage and performance requirement of frequency synthesizer, the design projects and methods will be multiform,The thesis encloses a specific engineering design, integrates factors and adopts a new way to solve the specification contradiction, then realizes it. It includes:1. The thesis gives a brief introduction to the development history of frequency synthesization technology, and introduces basic theory of two common frequency synthesization technologies: direct digital frequency synthesization (DDS) and phase-locked loop (PLL) frequency synthesization. Moreover, The thesis analyses the features of the two technologies, especially to some important specifications, such as phase noise and spur.2. The thesis researches and analyzes the realization methods for mixing synthesization technology of PLL and DDS. Combining the performance specifications which the thesis should realize and integrating the advantages and disadvantages of each method, the thesis puts forward an innovative method. This method integrates double frequency, divide frequency, DDS driving PLL, and mixing frequency inserting PLL, etc. Meanwhile, it analyses realization possibility of this method by some important specifications. According to analysis, the method can satisfy the specification requirement of the task.3. Complete the experiment study of the design, especially analyze the selection of device, circuit design emulation, module circuit debugging and associated debugging for whole system. The actual test result indicates that this design can realize the specifications and meet system requirement. 4. It analyzes some problems which should be paid attention to in engineering design.