Research On Substrate-integrated Waveguide Power Division Filter Devices For RF Front-end Systems

With the development of wireless communication system,the design requirements of high-performance and miniaturized RF circuits are higher and higher.Among them,the filter and power divider as an essential part of RF front-end system of two passive components,with functions of frequency selection and power division,However,simply cascading them in the same system may cause mismatch.In order to solve this problem,the filtering power divider that integrates the two functions came into being.In addition,the Substrate Integrated Waveguide(Substrate Integrated Waveguide;SIW)technology combines the advantages of easy integration of planar microstrip technology and the advantages of high frequency and low insertion loss of three-dimensional waveguide technology,attracting analytical method.In view of the shortcomings and defects in the design method of SIW filtering power divider at present,this paper proposes some efficient and superior design methods.Finally,a series of new superior performance,simple structure and multi-functional SIW filtering power dividers are designed in the form of single-layer or double-layer circuits.Summarize the main contents of this thesis,which can be divided into the following aspects:1.Based on the improved single-sided public filter coupling topology model,a novel design of filtering power divider suitable for odd and even output ports is studied.Firstly,on the basis of the simplified topology a two-way SIW filtering power divider working in the U-band is designed using the double-layer single-mode SIW-microstrip transition structure.The output ports do not interfere with each other by loading isolation resistance between the output coupling lines.Additionally,the even-/odd-mode analysis method is introduced to verify impedance matching and calculate the theoretical value of the isolation resistance.Then,in order to increase the number of output ports,a three-way equal/unequal filtering power divider using a single-mode SIW cavity is proposed based on the above topology structure.Particularly,this circuit can achieve adjustable power division ratio.Ultimately,on the basis of the analytical method,the simulation and test of the two devices are carried out to verify the effectiveness of the design method.2.Based on the"multi-mode of one cavity"coupling topology,a novel design of a new multi-band SIW filtering power divider using a single multi-mode SIW resonator is studied.Firstly,the first six modes are perturbed by introducing metal through vias in a single SIW resonant cavity,and the resonant frequency is changed,then make it two-by-two combination to design a three-passband filter with adjustable passband center frequency and bandwidth.In addition,we introduce the complementary split-ring resonant(CSRR)and analyze its resonance characteristics,then the combination of CSRR and two SIW self-resonance modes to design a dual-band SIW filtering power divider in a single cavity.Good port-to-port isolation effects is achieved by loading a resistor.According to the design steps,three-dimensional modeling simulation,processing and testing have been carried out to verify that the two designs have the advantages of high performance and miniaturization.3.Based on the coupling topology of balanced function implantation,a novel design of SIW balanced-to-balanced filtering power divider with high isolation is studied.Firstly,the conversion relationship of the mixed-mode S-parameter scattering matrix of the six-port balanced network is analyzed.Then based on the single-layer single-mode triangular SIW resonator,a single band balanced-to-balanced filtering power divider with high common-mode supression is designed,and high isolation is achieved by adding resistors between the two inverting ports of the two pairs of differential output ports.On this basis,by using TE₂₀₁-mode and TE₂₀₃-mode of the multi-mode SIW resonator,a dual-band balanced-to-balanced filtering power divider is designed using double layers.By adding two resistors diagonally,good in-band isolation is obtained.According to the above design mechanism,simulation,machining and testing on the two designs are carried out,and verifies that they have certain advantages in common mode suppression,port isolation and return loss.