The Research Of Dual-channel Filter Based On RNS System

It is about the problem that interferometer direction finding techniques faced in actualengineering application. It mainly studies on two aspects of the direction finding method ofthe special platform interferometer when calibration method of multi-channelamplitude-phase mismatch and corresponding solutions are proposed. The proposedmethods are tested and their feasibility is proved adequately.①Direction finding method of interferometer is proposed based on the specialplatform: such as PRS (Passive Radar Seeker), airborne platforms antenna lineup restrictedplatform structure, the antenna elements are often disposed only in certain regional platform,which the Direction finding antenna array design lineup made high requirements. Thispaper analyzes the defuzzification method of the traditional land-based interferometer systems and compares the advantages and disadvantages,in order to find the defuzzification met-hods suitable for interferometer with special platform. Due to limited the space lineup ofseeker, virtual method of baseline is proposed to solve the contradiction between maximumunambiguous angle of view and finding the direction bandwidth, the condition of correctlysolving ambiguity of SNR requirements and channel phase consistency is analyzed, andaccording to the conditions, a non-uniform L-shaped array is designed which has a good theeffect on direction-finding. Also, according to the characteristics of airborne platform, fiveuniform elliptic array model is given, and the ratio between elliptical array aperture and thewavelength whether has impact on estimation performance of the incidence angle isanalyzed, conclusion is drawn that increasing the aperture of array within a certain aperturecan improve the accuracy of finding the direction, then fourth-order cumulant MUSICalgorithm is introduced to increase the aperture of the virtual array to solve the problem offinding the direction with the limited antenna dish volume, effectiveness of this algorithm isverified in the interferometer of elliptical array model by the simulation.②Contoured surface for multi-baseline interferometer using multiple receivechannels, the channel consistency is difficult. This paper analyzed the error of amplitudeand phase of the five-channel uniform circular array interferometer. Also it has given a briefof algorithm of channel correction which used commonly. Due to existed deficiencies of LSalgorithm in terms of the correction, the paper put forward the application of the total leastsquares (TLS), the overall weighted least squares (WTLS) algorithm which is applied to correct the error of amplitude and phase of five-channel uniform circular arrayinterferometer and completed comparison of correcting performance of TLS algorithm andLS algorithm. Also the paper proposed a new direction of application of TLS and WTLSalgorithm.Finally, we summarized the main contents of this study, and pointed out the issue tocontinue further work remains to be studied.