Study On The Wideband IF Signal Sampling And Processing Technology

In modern wireless communication systems, High-speed is proposed for the data acquisition system by the transmission requirements of the large number of real-time signal. An effective way that satisfies the requirements of high speed is the broadband capture technology. With the development of software radio, We need to sample and deal with the IF signal as well as RF signal. Now, the broadband acquisition and processing system of IF signal meet the demand. The objects for wideband IF signal sampling system is a IF signal with higher sampling rate, so there is requires a wide enough band for the sampling system to sufficient the high-speed signal, while the wide bandwidth will bring noise,harmonics and other effects, it make the design difficult. In this paper, I aim at the question of wideband IF signal sampling and processing system, first of all I start with sampling theory, and analyze the application methods of sampling theory in the band-pass sampling system, and combined with the ADC category specific analysis the use of ADC——Successive approximation (SAR) ADC, Flash ADC(sometimes called parallel ADC), Subranging (Pipelined) ADC and the∑-△type ADC, I select the Pipeline Model AD9640 as the core device of analog-digital conversion circuits. By studying the input matching condition of the analog front-end, select the transformer as the converter of the input signal from a single-ended signal to differential signal; and consider the needs of an integrated circuit clock, analysis the impact of the clock error, calculate the range of the clock jitter; isolate power supply and ground noise; and consider the layout of the devices on PCB board, consider the influence of each other, consider the routing rules of high-speed signal and analog-digital mixed design considerations; and give particular attention to the anti-aliasing filter which plays a significant role to ensure the quality of wideband signal acquisition systems, and study more detailed. Finally, I give the optimization analysis and design of key technologies which improves the deficiencies in the design.