X-band Phase-locked Dro Frequency Source Research

With the continuous development of radar, communications and other modern electronic systems, seeking to lower phase noise and high frequency stability of the local oscillator become the main trend. DRVCO due to its excellent phase noise performance and high frequency stability is widely used in frequency synthesis and microwave frequency sources. Using phase-locked technology to lock the DRVCO at high stability crystal locked frequency reference source, we attain at high stability,low phase noise microwave frequency source.The purpose of this research topic is to design a low phase noise X-band phase-locked DRO frequency source. Based on the explicit formula for the oscillator phase noise, we summarize the factors that affect the oscillator phase noise and some methods are proposed to improve oscillator phase noise. Then, a 10 GHz DRO is designed and implemented by using field simulation software HFSS and ADS circuit simulation software. After the designing of a phase-locked loop to lock the DRVCO, we get a low phase noise microwave point Frequency source.In the theory part, the basic analysis method of microwave oscillators are presented, which consist of the following three methods: the positive feedback theory, negative resistance theory and two-port network theory of S parameters. Following the basic theory of oscillator is the major technical indicators of oscillator,the principle of dielectric resonators,dielectric resonator parameters and its basic circuit. Based on this theory, then the X-band DRO is designed, including the dielectric resonator with HFSS field simulation,ADS oscillation circuit simulation,the buffer amplifier design,the design of directional coupler and the PCB layout drawing and fabrication of DRVCO. We measure and debug the DRO. In the last part of this thesis, we present the basic principles of phase-locked loop and design a phase-locked loop to lock on the previously designed DRVCO and debug the phase-locked loop, analyzing the final results, summarizing problems in design, pointing out the direction for the next step.