Study Of Remote Virtual Frequency Sweeper Based On Fpga And Flex Technology

Frequency sweeper can be used to measure the frequency characteristics of network system and electrical system, which is applied to engineering practice and teaching research, and plays an important role in measurement and control field. But the tradition frequency sweepers are always too expensive to buy and to maintain, not convenience to cany, too complex to operate and have few low-middle frequency bands products. Based on these problems, this paper combines the network technology and virtual instrument technology, does a lot of research on the network architecture, system components and realizing solutions, puts forward a new design method of frequency sweeper, and have realized the remote virtual frequency sweeper system by FPGA and Flex technology, and so on.This paper gives details of the system’s design concept, the whole framework and the software and hardware design.The whole system adopts B/S framework and includes three major parts: the DDS signal source part, the terminal software design part and Web Server part. The DDS signal source part uses the ARM and FPGA as the control center, applies DDS technology to generate signal source and contains ARM control module, signal generator module and signals acquisition module: The signal generator module can be divided into FPGA control module, D/A transform module and gain adjusting module. The terminal software design part utilizes Flex as the development platform which supports the development and deployment of Rich Internet Application, including the design of virtual instrument’s front panel, data processing on Server and WebServiee communication protocol between ARM and Web Server. The test results show that the frequency resolution of the sweep signal source generated by the system can be up to1Hz, and the frequency range is1Hz-2MHz which can be used to measure the amplitude-frequency characteristics of the low and medium frequency networks or electrical system, and the corresponding amplitude-frequency curves can be displayed on Web page. In addition, this system can also be combined with the remote laboratory system, serving as the arbitrary signal source generator. The virtual sweep generator has many advantages, it is low cost, convenient operation, with good man-machine interface and easy to expand, and so on. The system can compensate for the situation that there are few low and medium traditional frequency sweepers on the market, so it has strong practical significance.