Research On Balun With High Performance

With the continuous advancement of information technology and the continuous development of communication systems,the exchange of information and data between people and things cannot be separated from communication.The communication industry has clearly become one of the most popular research fields today.As one of the important devices in communication systems,antenna systems,and radar heartache,Balun has outstanding effects in improving communication quality and reducing interference.Many balanced devices such as ultra-wideband antennas and balanced filters require Balun to convert unbalanced signals into balanced signals.High performance balun can play the role of matching,conversion,and isolation,which has clearly become a topic of exploration and research at home and abroad.In this thesis,the research goal is to design a high-performance balun with broadband miniaturization and a hybrid slot line structure and waveguide structure as the design basis.This thesis mainly focuses on four parts:The first part starts with the relevant research background of the industry’s demand for Balun,and briefly analyzes the research status and development trend of Balun;Then,the basic properties and characteristics of microstrip lines,slot lines,and rectangular waveguides needed in this article are introduced;Secondly,using the odd and even mode analysis method to analyze the scattering matrix satisfied by a four-port network,and combining with the formula that must be satisfied by a three-port device,the Balun scattering matrix is derived in detail.Then,combining with the operating characteristics of a passive Balun,nine inferences and two important conclusions are obtained.In the second part,first of all,combining the basic properties of microstrip lines and slot lines,the coupling principle of microstrip line to slot line structure is analyzed using the electromagnetic field distribution,and an equivalent model of this structure is proposed to explore the influencing factors of center frequency and coupling strength;Then,the wave equation is used to derive the propagation mode,phase constant,cutoff frequency,etc.of the rectangular waveguide,and simulation verification is performed using HFSS and ADS;Then,the effectiveness of the equivalence process is verified by analyzing the substrate integrated waveguide equivalent to a rectangular waveguide,and the influence factors and characteristics of the center frequency of the propagation mode of the substrate integrated waveguide are summarized.In the second part,first of all,combining the basic properties of microstrip lines and slot lines,the coupling principle of microstrip line to slot line structure is analyzed using the electromagnetic field distribution,and an equivalent model of this structure is proposed to explore the influencing factors of center frequency and coupling strength;Then,the wave equation is used to derive the propagation mode,phase constant,cutoff frequency,etc.of the rectangular waveguide,and simulation verification is performed using HFSS and ADS;Then,the effectiveness of the equivalence process is verified by analyzing the substrate integrated waveguide equivalent to a rectangular waveguide,and the influence factors and characteristics of the center frequency of the propagation mode of the substrate integrated waveguide are summarized.In the fourth part,a half wave folded resonator element is proposed to optimize the size of the Balun;Then,the resonant frequency points of the dual E slot line resonator element are introduced and derived,and the effect of introducing it into the hybrid balun on broadening the bandwidth is verified.Finally,a hybrid slot line and half wave folded resonator structure with dual E slot line resonant elements is proposed.