Design And Implementation Of Dual-channel Orthogonal Signal Source Based On FPGA And DDS Technology

The dual-channel orthogonal signal source can generate single-channel or dual channels orthogonal single tone signal,FSK signal,automatic triangular linear sweep signal and BPSK signal.Single-channel signals are widely used in radar,aerospace,electric power,communications,radio and television,as well as in medicine,industry,agriculture and other fields.Two channels orthogonal signals are widely used in the quadrature modulation,quadrature signal MIMO radar,radar receivers,radar phase discriminator and other occasions.A dual-channel orthogonal signal source is designed in this dissertation,and the design scheme based on FPGA and DDS technology is put forward.The AD9854,a highly integrated chip dedicated to DDS,is used to realize the output of single-channel or two-channel orthogonal single tone signal,FSK signal,automatic triangular linear sweep signal and BPSK signal.Firstly,this dissertation introduces the development history and realization method of the signal source,compares the advantages and disadvantages of various implementation methods,introduces the technical indicators of the signal source,and then elaborates the composition and working principle of the DDS,introduces the function,the feature and the controlling technical principle to AD9854 of high integration and high cost performance DDS chip AD9854.And then the hardware design and software design of the system are described in detail;finally the system hardware circuit as a whole connection is completed to achieve the function that change the signal parameters of the host computer to control system output signal.The methods of test system function and performance and experimental results are given.Through the experimental debugging and testing,the design can produce a high degree of stability of the single-channel or dual channels orthogonal single tone signal,FSK signal,automatic triangular linear sweep signal and BPSK signal.The output signal frequency is up to 40 MHz,the peak-to-peak value can be up to 5V,the signal stability is up to 10-4.The design can be widely used in single-channel signal sources and dual-channel orthogonal signal occasions,and it can provide design support for signal source.