Research And Design Of New Reconfigurable Power Division Filter In Wireless Communication System

With the rapid development of wireless communication system and satellite navigation system in military and civil fields,the RF front-end system puts forward great demands and challenges to the integration,multi-frequency and multi-function design of microwave devices.In this context,the reconfigurable filtering power divider came into being.Due to its small size and various functions,it has attracted more and more researchers'attention.However,there is still a lack of effective reconfigurable network topology and its integrated design method.In order to solve these problems,a variety of excellent shared tunable resonant cell network topologies are proposed in this thesis,and a series of new high-performance reconfigurable filtering power dividers are designed comprehensively,which can effectively achieve reconfigurable center frequency(CF),passband bandwidth(BW),power divider ratio(PDR)and other indexes.The integrated design of the reconfigurable filtering power divider proposed in this thesis can not only improve the performance of the existing methods,but also simplify the design and reduce the circuit size.The main contents of this thesis are summarized as follows.1.A reconfigurable filtering power divider with adjustable center frequency and bandwidth was designed based on the shared tunable branch loading resonant element network topology.Firstly,a reconfigurable filtering power divider with adjustable center frequency and bandwidth is designed based on a branch loaded three-mode resonator by using the proposed network topology mechanism sharing adjustable resonant elements.By means of odd-even mode analysis method,the theoretical equation of three-mode resonator is derived,and the filtering response and key control elements are obtained from the calculated formula.Secondly,using the odd-even mode analysis method to analyze the whole circuit,so as to obtain the impedance matching and the theoretical value of the isolation resistance of the circuit.Finally,carry out three-dimensional modeling and simulation verification,as well as physical processing and testing.In addition,we also preliminarily conjecture and theoretical analysis on the reconfigurability of the power divider ratio.Finally,three-dimensional modeling and simulation verification,as well as physical processing and testing,the comparison of the simulation and test results,verified the effectiveness of the design.Compared with the reconfigurable filtering power divider reported in the literature,the reconfigurable filtering power divider avoids the variable coupling between the resonant node and the external input/output.Not only it has better performance,but also the topology is more compact and concise,the number of resonators and loaded varactor diodes is reduced.2.Based on the shared tunable lumped element resonant cell network topology,a comprehensive design of a reconfigurable filtering power divider with adjustable center frequency and power divider ratio was developed.Firstly,the resonant circuit composed of lumped components is analyzed,and the variable capacitance is introduced to analyze the filtering response of the resonant circuit.By using the proposed network topology of shared tunable resonant cells,a single parallel LC dual-mode resonator is designed,and the second-order filtering response with tunable center frequency is realized.On this basis,combined with the conjecture and theoretical calculation of the reconfigurability of the power divider ratio in the previous part through the analysis of the coupling coefficient and external quality factor in the non-normalized variable coupling coefficient matrix,the input/output coupling of the circuit is skillfully controlled,and the continuous adjustable power divider ratio is realized.The best impedance matching and isolating resistance of the circuit are obtained by using the odd-even mode analysis method.Finally,the actual processing and testing are carried out,and the test results are in good agreement with the simulation results.As a result,comparing to the traditional design,the number of diodes reconfigurable filtering power divider is greatly reduced and circuit dimensions are very compact(0.12?_g×0.12?_g and 0.05?_g×0.07?_g).3.Based on the network topology of shared tunable ring resonator cells,a reconfigurable filtering power divider with fully tunable center frequency,bandwidth and power divider ratio was designed.Firstly,the coupling line resonator loaded with a ring is summarized.The S-parameter of its coupling topology is analyzed.And then combining the advantages of the first two devices,a reconfigurable filtering power divider with fully adjustable center frequency,bandwidth and power divider ratio is designed based on the network topology of shared tunable resonant unit.The resonant frequency is precisely controlled by deducing the theoretical equation of the ring resonator.The filter response with adjustable center frequency and bandwidth is obtained.On this basis,the coupling coefficient and external quality factor of the coupling topology are analyzed,and the variable dual output coupling is introduced by loading the varactor diode.And the continuous adjustable power divider ratio is realized.Then,the method of odd-even mode analysis is used to analyze the reconfigurable filtering power divider,and the better isolation and impedance matching results are achieved.Finally,by carrying on the 3D modeling simulation,implementing and measuring a prototype,the design principle,simulating and measuring results of the reconfigurable filtering power divider are introduced in detail.The validity of this design is verified.It provides one promising solution of high operation performance,miniaturization and design flexibility enhancement etc.,for industrial multi-functional modern wireless communication systems.