Design And Implementation Of Wideband High Resolution Frequency Synthesizer

In order to meeting the requirements of different clock signals in automatic test systems,this paper has studied the key technologies of low noise frequency source,and given a low phase noise clock signal generation method.On this basis,a multi-output low noise synthesis frequency source is designed to achieve a number of high-precision,low noise clock signal output.In this paper,the key techniques of low noise multi-output synthesis frequency source are studied,including the comparison of various frequency synthesis methods,the principle of phase-locked synthesis frequency source and the link of noise are analyzed.And source also resolved the output module and synthesis frequency source noise suppression.Then,through the simulation analysis and comparison of the principle of different schemes,the low noise synthesis frequency source of multi-output is designed and realized.Finally,the key difficulties in the design and debugging are analyzed.The main contents of this paper include the following aspects:First,multi-channel signal output frequency synthesis system are designed.The frequency synthesis system is the core of design process of the synthesis frequency source.In this paper,the characteristics of a variety of frequency synthesis methods are analyzed and compared.Through the source combined with the actual demand,the circuit structure of multi-channel independent phase-locked loop circuit plus clock buffer is adopted to realize the synthesis of target frequency and output through independent signal conditioning channel to ensure that the output signal meets the technical requirements.Second,the phase-locked loop circuit of system analysis and control module are designed.The characteristics of phase-locked loop circuit analyzed and simulated.And the influence of the loop filter on the phase noise and the locking time is studied.And the paper gives the frequency control word write method and control circuit.Third,the output signal of low noise are designed.The influence of the output signal phase noise is analyzed,including the signal generation circuit,the signal amplification,the filter circuit,and the power supply and so on.A low noise design is performed on the main circuit that affects the phase noise of the output signal.Fourth,a complete hardware circuit are achieved.And the paper carried out debugging and testing.The design scheme of synthetic frequency source for multi-channel signal output is verified,and the problems and solutions in the debugging process are summarized.After testing to verify,all the output signal frequency accuracy are within 0.1ppm.The output signal power and phase noise indicators meet the requirements.Through the multi-output scheme given in this paper,the accuracy of the output signal of 10 MHz is within 0.02 ppm,and the delay between the output signals is within 100 ps.And through the noise reduction of the output signal,the channel phase noise optimization are better.