Design And Development Of High-speed Wideband Frequency Synthesizer

Based on the development requirement of new V/UHF radio,a broadband high-speed frequency synthesizer is studied and developed.In the thesis,the specification requirements for broadband output,fast frequency conversion and good spectrum quality are discussed.The development of frequency synthesizer is analyzed.As a result,a PLL scheme is presented and a detailed circuit and PCB design is completed to realize efficient balance among these indicators.The research on broadband frequency synthesizer is successful,which can meet application requirement of new radio.The followings are brief introduction of the research.1.Research completed the project design.The advantages and disadvantage of existing frequency synthesizer are analyzed,and then technical features of the project are combined to determine the design scheme.The latest frequency synthesizer integrated circuit in Hittite is chosen as core in first local oscillator PLL system.PLL circuit ADF4106 with good phase noise performance and integrated VCO with high resolution are chosen to ensure phase noise and spurious performance of output frequency of second local oscillator.According to the radio requirement for clock signal,a temperature compensated crystal oscillator of 38.4MHz is chosen as reference frequency of first and second local oscillator.Meanwhile,the reference frequency can be used as clock signal of complete set.The four-channel output linear voltage regulator featuring ultra-low noise and four-channel independent output,is an outstanding regulator and can power frequency synthesizer unit.2.Completed the realization of the key technologies and breakthroughs.Loop filter simulation tool is used to realize the design of loop filter.VCO output frequency dividing ratio is set and control algorithm and time sequence of PLL circuit is given according to bandwidth distribution of local oscillator frequency.The output frequency and spectrum quality is taken in consideration in the second local oscillator.The detailed design of the circuit and PCB are completed in accordance with scheme demonstration.a reasonable layout of PCB is given according to functional characteristics of the circuit.the wiring rules,shielding have been comprehensively considered to improve anti-jamming performance of the PCB in design.the access method of power processing filter components,the layout of the loop filter and wiring requirements are specified because of a large amount of filters and the circuit board is designed based on rich experience.3.The product function indexes of testing and validation.Debugging and system test are carried out for completed circuit board.Then,test data and patterns are sorted out,showing that the frequency synthesizer unit can meet technical and system application requirements and the thesis research is completed.The frequency synthesizer development has achieved technical breakthrough in the field,providing technical support for new V/UHF radio development.Thesis research work full implementation of the subject.Adopting the advanced technical line,the results of the study has reached the expected goals,can be successfully applied in the actual product development,enhance the level of communication radio research techniques.