The Realization Of Frequency Spectrum Analyzer Instrument Based On Software Radio

With the rapid development of communication, especially the mobile communication technology, RF frequency spectrum analyzer as communication measurement instrument in the research, manufacture and maintenance of the communication equipment is needed urgently, and its application is wider and wider. The frequency spectrum analyzer should have some characters such as flexibility, openness and compatibility. The traditional spectrum analyzer was difficult to realize these function but we can solve it by used the ideal of software radio.This paper discusses the realization of the RF frequency spectrum analyzer. The architectures of the receiver are RF pass band direct sampling and IF pass-band sampling with high-speed analog to digital converter after RF to IF conversion. The first kind of architectures is hard to realize because of the requisition of devices is too high. Then it will do some other digital process. The evolution of programmable hardware and increased flexibility via increased programmability has been accomplished by a cpmbination of techniques. These include multi-band antenna and RF conversion, wideband analog to digital (A/D), and digital to analog (D/A) conversion. This paper first expatiates on the theory of software radio, discussing the Multi-rate Digital Signal Processing, High-speed Data Acquisitions, digital down converter. Then on the basis of those, a model of software radio receiver is given. Operations are determined using hardware whose configuration is under software control. Finally, the circuits are realized with hardware, in order to prove the discussed schemes.The paper shows that the software radio system has the flexibility, openness and compatibility in processing the multi-band and multimode signal, and indicates that FPGA is especially suitable for the standardized designing of SWR with its advantage of reconfiguration and parallel processing.