Research On Key Technologies Of Wideband Digital Channelized Receiver System

Digital channelized receivers provide the desirable characteristics of broadband frequency coverage,high sensitivity,large dynamic range and simultaneous signal processing capabilities,which can be widely used in many Electronic Warfare(EW)applications.Thus,much research and various design approaches of the digital channelized receiver have been proposed in recent years.The main contributions of our work can be summarized as follows:1.We completed the design of microstrip filters for digital channelized receivers' front-end analog circuit.A new method for designing stubs loaded filters is presented,which is achieve by reflection coefficient analysis and parameter optimization.Additionally,stepped impedance resonators are used as the basic resonance unit and the design of dual-passband filters with controllable passband is realized.The proposed filters combine the characteristics of miniaturization and good performance.2.The theoretical foundation of digital channelized receivers,i.e.,the multirate signal processing theory,is introduced.Based on this theory,the hardware-efficient digital channelized architecture using the polyphase filter banks is deduced and established.Then,channel division method and channel detection method are given.Finally,we focus on the design of reconfigurable filter banks.The perfect reconstruction condition of DFT filter bank is analyzed and discussed.3.Frequency-response masking technique(FRM)provides a good solution for the realization of digital filters with narrow transition band.Based on this,a new masking principle is proposed by us.The advantage is that there is no need to optimize the filter coefficients,and the reconfigurability of the FRM filter banks can be guaranteed.Meanwhile,an alternate masking strategy for even channel and odd channel is given,which simplifies the process of the FRM filter bank design.When generating the FRM filter banks,only the masking filters are needed to be modulated,and the interpolation multiple can be any integer.4.Two efficient channelized architectures are deduced and verified by us.On the one hand,by using the new masking principle,the perfect reconstruction property is easily satisfied.This non-uniform channelized architecture can be widely used in multi-standard wireless communication system.On the other hand,an FRM-based two-stage channelized architecture is proposed for extracting individual channels from the wideband input signal,which combine the characteristics of high sensitivity and small channel aliasing.Simulation results are provided to demonstrate the reliability and efficiency of the proposed method.