Fpga Applied Research In Nuclear Magnetic Resonance Spectrometer And Cpt Frequency Standard

With the wide application of Magnetic resonance technology and atomic frequency standard in their respective fields,people's requirements on the experimental apparatus design are become more and more . NMR Spectrometer for example , in order to meet the experimenter of different views and demands, the home_built NMR spectrometers have been designed .For Atomic Frequency Standard,the electronic systems of it not only need to be able to complete the precise frequency and phase-lock function, but also the need to achieve the miniaturization of the design. So this thesis aims at the research on FPGA design method and application in NMR Spectrometer and CPT rubidium atomic frequency standard.This research aimed at FPGA in the NMR spectrometer digital RF transmitters and CPT rubidium atomic frequency standard digital control circuit.After analying the common problems of these two fields,a design method is presented.Utilizing embedded blocks such as RAM and the resources of logic gate of the FPGA and basing on ARM7 and other communication systems, the realized NMR digital orthogonal transmitter will be able to provide accurate high speed pulsed output with FM, PM or AM. Synchronously controlling two pieces of DDS using the FPGA, the transmitter will also be able to provide orthogonal RF output.The DC / microwave scanning and lock functions in CPT rubidium atomic frequency standard are also realized by using FPGA to control DDS,DAC,ADC chips.In this paper the design is verified by simulation and measurement results. Under this design framework the interface with DDS and ARM can be flexible switched,and the design period can be shortened to some degree.