Research On Dual Frequency Power Division Technology With Out Of Band Suppression Function

RBN local differential precise positioning technology has the advantages of accurate positioning,high reliability,good real-time performance and low cost,and it is widely used in national economic production and other fields.RBN local differential precise positioning needs UHF-band satellite positioning data and LF-band differential correction data to achieve precise differential positioning.Ultra wide band dual-band antenna which can receive satellite positioning data and differential correction data at the same time can reduce the system cost and improve its reliability,which requires an ultra wideband resistive power divider to receive UHF-LF mixing signal at the same time and effectively divide the mixing signal to obtain satellite signal and beacon signal in real time to analyze satellite positioning information and differential correction information accurately.However,due to the low isolation of output port and the inability to suppress non UHF-LF interference signals of resistive power divider,the accuracy of positioning information is reduced and the potential risk of poor positioning accuracy is introduced.So,it is of significance to design UHF-LF frequency power divider with out of band suppression to improve the precision of RBN local differential positioning.To realize UHF-LF ultra wideband dual frequency power division,Wilkinson power division technology is analyzed based on three-port network and S-parameter theory.The comprehensive correction method of UHF Power Division Based on RBF-ANN is studied to estimate the frequency deviation of power division center caused by the design deviation of microstrip line parameters,and the comprehensive correction model of UHF Power Division is modeled to correct the center frequency accurately.Then,by analyzing of the demerits of resistive power divider in detailes whose port isolation is low and inability in suppresseing interference signal,a modified UHF-LF Ultra Wideband Microstrip power divider method is studied based on Wilkinson power divider technology,and all-new UHF-LF ultra wideband dual frequency power divider is designed.Moreover,simulation analysis is carried out with ADS simulation analysis technology to verify its function and performance.To eliminate the impacts of non UHF-LF band interference signal on the accuracy of satellite positioning information and differential correction information,taking the microstrip line filter as the breakthrough point,the effect of microstrip defect structure parameters on its filtering efficiency is studied with ADS.Stopband comprehensive adjustment model based on RBF-ANN is built with microstrip defect structure and its efficiency deviation.According to the model,the parameters of microstrip defect structure are optimized to ensure its accurate filtering ability.Then,the optimized microstrip defect structure and UHF-LF ultra wideband power divider are combined to form the dual frequency power division technology with out of band suppression function.Also,ADS simulation analysis technology is used for simulation analysis and verification to ensure the realization of dual frequency power distribution and out of band suppression function.In order to verify the dual frequency power division technology with out of band suppression function,a verification platform of dual frequency power division technology with out of band suppression function is studied and implemented,including power division module,GNSS related data analysis module and auxiliary module.Due to the requirements of functional and performance,the hardware circuit of each module is designed in detail.According to the requirements of the hardware and the electrical parameters of each module,the circuit is desigend in details and implemented.Then,the performance evaluation tests are conducted to test the dual frequency power division technology with out of band suppression.The test results show that insertion loss,port isolation and VSWR of dual frequency signal meet the requirements of dual frequency power division technology with out of band suppression 11% and 116.7%?117.3% and 9%,and its port isolation is increased by at least one time which suppresses non UHF-LF interference signal effectively.Hence,it has better UHF-LF dual frequency power division and out of band suppression functions.