The Design And Research Of Program-controled Spectrum Analyzer

Spectrum analyzer is regard as the multimeter of frequency domain, widely used in practice production and scientific research. So this design is mainly in designing one kind of low-cost, portable, programmable spectrum analyzer, which well meets general public demands. It can translate the time domain signal into frequency domain signal, and the spectrum ,phase spectrum as well as the original signal can be displayed on the LCD screen.S3C44B0X of ARM7 series produced by Samsung Co. and EP2C8Q208C8N of Altera Cyclone II family is selected as the core of the hardware design, including ARM+FPGA peripheral circuit design, the design of A/D acquisition module, the signal conditioning module, the design of interface, and keyboard design, GPIB interface board's research. Software design of the system included the control program of ARM used language C, FPGA internal procedures and the protocol of GPIB Interface communication adopted Verilog HDL language and graphic description, and opted Lab Windows /CVI realize the control of host computer interface. Ultimately, 640*480 color LCD adopted to display the graphical of frequency domain signal with friendly interface as well as easily to control. As a programmable instrument, it not only realized local control but also finished remote control. While in remote control mode, through the common interface module insided the device, it can be connected with TCP/IP,GPIB,USB connector developed by our own lab, and assembled into a multi-interface programmable automatic test system.Using Quartusâ…¡9.0 software of Altera Co. and adopting top-down design thought accomplished FFT processor design based on FPGA. Fast Fourier Transform was selected to translate time-domain signal into frequency- domain signal, and so implementation of FFT algorithm based on FPGA is the core of the design. To make full use of FPGA internal resources, the designing of data buffer, adding window, reverse, butterfly transformation and cordic algorithms modules were finished based on FPGA. So the processing speed can be improved and processor performance can be guaranteed. Finite state machine was adopted to control the whole flow, not only ensured the isochronous of FFT transform, but also made each module much more harmonize and stable. Using Quartusâ…¡9.0 software and adopting top-down design thought accomplished FFT processor design based on FPGA.In this paper, all of the above-mentioned contents were discussed in detail, and though analysis of test- result validated its superiority; what's more, by comparing the test- result and simulate-result of Matlab verified the practical as well as usefull value of the design.