Research On Multi-channel Technology Based On Hybrid Filter Banks ADC System

With the rapid development of radar,software radio and modern digital signal processing technology,people on the ADC sampling accuracy requirements are getting higher and higher.Parallel sampling system based on hybrid filter banks is one of the effective methods to realize high-speed and high-precision sampling.This thesis systematically studies the multi-channel sampling system based on hybrid filter banks.The design methods of analog filter and digital filter are analyzed emphatically,and the design sampling system is optimized by structural simplification and error correction.Finally,a four-channel sampling system based on hybrid filter banks is obtained by simulation.This article reads as follows:1.Based on the parallel sampling system and basic sampling theory,the multi-channel ADC system based on hybrid filter banks is analyzed in detail,and the reconstruction condition of the system is deduced.2.Because the difference of multi-channel sampling structure lies in the design of analog filter,three multi-channel implementations are studied: traditional structure and modulation structure based on ideal frequency characteristics,and power complementary structure and extended structure based on power complementary technology.And simulation comparison to analyze the advantages and disadvantages of these three implementations.It is concluded that the modulation structure and the power complementary structure can achieve high speed and high precision sampling under certain conditions.3.According to the reconstruction condition,the design methods of three kinds of digital filters,such as inverse Fourier transform method,minimum maximum value method and total least squares method,are analyzed.Through theoretical analysis and simulation comparison,the total least squares method is the most excellent design method.At the same time,the influence of the actual error on the sampling system is analyzed,and the frequency band weighting method and the band correlation correction method based on the single channel filter extended structure are proposed to optimize the design system structure and reduce the influence of the error on the system,thus improving the sampling accuracy of the ADC sampling system based on the hybrid filter banks.4.In order to verify the sampling performance of the designed four-channel sampling system,the RLC circuit design method of the analog filter and the digital filter design method based on the simplified multiphase filter structure are analyzed in detail.After the actual error is corrected by the frequency correlation correction method,Software on the digital filter to be reconstructed signal,and finally the use of MATLAB analysis,based on the tree structure of the four-channel hybrid filter group ADC system to meet the 10 bits sampling accuracy requirements.