The Design Of Multi-mode Multi-channel Coherent Signal Generator Based On FPGA

The existing common signal generator can not meet the test requirements of special equipment,this master dissertation presents a FPGA-based high-speed DAC technology combined with a multi-mode multi-channel coherent signal generating method.The designed signal generator make full use of low-cost,high-performance FPGA logic resources with rich,fast,usable pin,high precision and programmable DDS IPCORE parallel processing,generating multi-channel arbitrary waveform signals and the phase controlled RF signals,and realizing high-speed digital to analog conversion by high-speed DAC.At the same time,using a high-speed DAC with a second Nyquist zone output function,such as AD9119/AD9129,realize ultra Nyquist output,expend the output frequency range.This master dissertation is organized as follows.The multi-mode signal generation FPGA design structure is introduced.To solve the DAC conversion rate is far higher than the operating clock existing FPGA devices issue in detail,a parallel DDS signal generator mode.According to the DAC conversion rate,designed number of parallel channels parallel signal generation process needs,and FPGA-based hardware resources and implementation,the detailed design of the structure of each pattern signal,and finally the use of Verilog HDL language to signal structure programming and simulation analysis,used to verify the correctness of the preparation of Verilog HDL language program.The multi-mode multi-channel coherent signal generator hardware design platform is introduced.The multi-mode,multi-channel technical requirements phase reference signal generator,introducing the FPGA,high speed DAC,two synchronous phase correction circuit hardware design,and introduces the more than two-channel design phase synchronization method based on and implementation.According to the DAC and the characteristic parameters and the first Nyquist zone,second zone and the output frequency response characteristics of the third region,by switching the DAC clock,the output signal of the extended frequency range to avoid the output signal frequency of 0.5 times the sample rate,sampling rate near 1 times and 1.5 times the sampling rate,the smaller the output power of the phenomenon.The multi-mode multi-channel coherent signal source output is tested.According to the mathematical principle of multi-mode signal and simulation result,multi-mode signal on the hardware platforms were tested output spectrum of multi-mode signal,and outputs time-domain waveform,the test results with theoretical multi-channel synchronous signal coincides Analysis in order to verify the feasibility and correctness of the design method.In summary,this paper designs and FPGA-based high-speed DAC technology combined with a multi-mode multi-channel coherent signal source has certain feasibility and value.