High Stability Based On Dpll And Dds Frequency Synthesizer Research And Implementation

High stability frequency synthesis has widely used in communication, radar, anti-electronic, navigation, radio, digital-TV, remote sensing, instruments, which is the heart of modern electronic system. As the boom development of electronic technology, more and more communication systems have to face the problem of the narrow density of spectrum electromagnetic spectrum, which has gradually increased the demands of the improvement of specification of frequency synthesis in several aspects, high precise and high stability of frequency output, low phase noise, rapid conversion, resolution, bandwidth, volume, power consumption and cost etc.Digital Phase Lock Loop (DPLL) is mainly composed of timing GPS reference and Oven voltage Controlled Crystal Oscillator (OCXO), the former has long stability and the latter has short stability, so the GPS reference can compensate the aging and wandering of OCXO when the DPLL is locked, which can output frequency with stability to 10^-10～10^-12. As the DPLL can only provide a single tone frequency which can not meet the demand of adjustment of frequency and phase, however, Digital Direct frequency Synthesis (DDS) can output multi-frequency with both high precise and stability.This thesis has gave a detailed description of realization of high stability frequency synthesis based on DPLL and DDS, which do not need any high precise clock and can not only provide the same precise and stability but also easy to realize. The frequency stability of DPLL and DDS can meet the requirement of system according to the simulation and circuit test.