Analysis And Design Of M-Channel Hybrid Filter Bank With Digital Calibration

Modern signal processing is becoming more and more digitization,and the requirement of analog to digital convert is higher and higher.In this paper,a multi-channel sampling system based on hybrid filter banks is studied.The feasibility of multi-channel structure and calibration algorithm is analyzed by theoretical analysis and simulation.Hybrid Filter Bank is widely used in Frequency-Interleaved analog-to-digital converter,in traditional Hybrid Filter Bank structure,the frequency band of input signal is uncomposed by analog filters.but there are varying degrees of imperfections in traditional Hybrid Filter Bank structure,such as band aliasing bring by overband of analog filters.This paper present a new-structure Hybrid Filter Bank based on power complementary pair.The proposed architecture only needs M-1 analog analysis filters in M-channels Frequency-interleaved analog-to-digital converter and the analog analysis filters satisfy the pairwise power complementary property.Therefore,this structure greatly simplifies analog circuits compared with traditional structure.Based on this structure,we put forward an estimation algorithm to estimate the channel mismatch errors and filter bank mismatch errors.Then calibration is carried out in digital domain.We conduct experiments by designing a Frequency-interleaved analog-to-digital converter system and the simulation results demonstrated the effectiveness of our proposed method.Average distortion error of-6.8192?10^-10 db and average aliasing error of-104.84 db can be achieved after calibration,resolution of this architecture can be up to 14-bit.