The Designing Of 30MHz～512MHz Broadband Receiver RF Front-end

The designing of RF (Radio Frequency) front-end is one of the key technologies of Software-Defined Radio (SDR). The ideal SDR is placing the A/D converter close to antenna directly and finishing all kinds of function by DSP software,but it is not feasible because of actual component's level. Converting the broadband RF signal to the IF signal which can be digital is the key to realize the SDR. Firstly,the basic principles and structures for SDR are discussed in the paper. And then explain the theory basis and key technologies of SDR concisely.By comparing RF front-end of some kinds of receivers and illustrating key technology fingers of how to estimate receivers, finally I decide which project I would adopt.In this paper, for 30MHz~512MHz broadband RF front-end, using fixed intermediate frequency super-heterodyne architecture and utilizing ADS2008 (Advanced Design System 2008) simulating, finally, a broadband RF front-end system simulation platform is presented, which provided the universal and modularization of receiver.