Dc - 3 Ghz Uwb Rf Receive Front-end Research

With the rapid development of third generation communication, the complex electromagnetic environment requires the receiver having the characters of wideband, catching low probability of intercept radar signal and processing multi-signals. Traditional analog narrowband receiver is unable to meet the modern needs, so it was only used in some simply applications. Gradually, Ultra-wideband receiver has started to replace the traditional receiver and become the mainstream of future development.This paper is focused on UWB-RF (Ultra Wide Band Radio Frequency) receiver front-end design. The researcher utilized DC-3000MHz UWB-RF receiver front-end by choosing secondary mixer super-heterodyne receiver architecture. The receiving chain includes low noise amplifiers, widely tunable pre-selection filters, mixers, IF filters, IF amplifiers and digital signal processing components. The local oscillator signal is generated by the phase-locked loop and direct digital frequency synthesizer.The paper detailed analyzed the UWB-RF receiver front-end system implementations. According to the allocation of system design specifications, analyzed the wide tunable structure of the pre-selection filters, proposed an improved scheme to meet the system design specifications. Low phase noise frequency synthesizer design is another focus of this paper. Detailed analyzed the characteristics of the output frequency of the PLL(Phase Locked Loop) frequency synthesizer and DDS(Direct Digital Synthesizer), and Provided an improved scheme which improved the linearity of the system.At last, conducted a detail test of the UWB-RF receiver system, and the results reached the design specifications, summarized the inadequacies of the system.