| The development speed of radio frequency microwave systems is increasing day by day,and the development direction is also increasingly pursuing wider frequency bands,higher density,and faster speeds,which makes the integration of components increase day by day,and the speed of intensive increase is getting faster and faster.Therefore,the problem of electromagnetic compatibility between various components is what needs to be solved.In the case of ensuring the normal operation of electronic devices,how to weaken the crosstalk between components has become a research hotspot.Based on the above research background,this paper will conduct research from the following aspects:1.Analyzed the basic characteristics of near-field radiation / coupling,and on this basis,constructed equivalent lumped circuit models under ideal and non-ideal conditions to solve mutual capacitance and mutual inductance.2.The coupling between the adjacent surface layer and the multi-layer board transmission structure is studied,and the coupling influencing factors of the surface layer transmission line and the multi-layer vertical transition transmission structure are analyzed respectively.Within the required index range,the simulation model was established by HFSS simulation software to study the structure of the parallel microstrip line on the surface single-layer substrate: by adjusting the spacing between the parallel lines to analyze the effect of the spacing on the coupling value,the results show that the spacing is increased Crosstalk between lines can be reduced;by adding RSR protective metal patch structure on the upper surface of the substrate,the effect of RSR structure on the crosstalk between adjacent parallel microstrip lines is analyzed.The results show that adding RSR structure can reduce coupling to a certain extent;The effects of the length and width of the RSR metal patch on reducing coupling were analyzed to investigate the effect of adding RSR structure on the coupling value on the surface.The results show that properly increasing the length and width has a better effect on the suppression of crosstalk;The way ofadding metallized grounding holes between them was investigated to investigate the effect of adding metallized grounding holes on the coupling.The results show that adding inter-board vias has a certain effect on reducing crosstalk;A comparative study of the influence of the ground wire on it shows that the effect is better than the structure with only through holes added;The effect of the corner of the transmission line on the signal integrity has reached the conclusion that the 45-degree angle cut has the best effect.3.The effect of double-row via structure under the condition of small line spacing is studied.The parallel microstrip line structure of the single-layer substrate is maintained at a distance of four times the line width,and the arrangement structure of the double-row through holes is studied.Use HFSS software to add two rows of metal ground holes arranged side by side and two rows of staggered metal ground holes in the middle of two parallel microstrip line models with a pitch of four times the line width.Impact.While keeping the radius of the metallized ground holes the same,change the center distance between each row of metallized ground holes to study the effect of the side-by-side structure and the staggered structure on the coupling.The results show that in a single row of through holes When the center-to-center spacing is greater than 0.8mm,the staggered structure has better suppression of crosstalk than the side-by-side structure;in the staggered structure,keep the center spacing of the single-row metal vias unchanged and change the coordinate value of the other row of vias In order to study the effect of the "three-point position" relationship in the staggered through-hole arrangement on the coupling,the results show that the "triangle position" is an isosceles triangle.4.The coupling between adjacent transmission structures in two vertical transition structures of microstrip-microstrip and substrate integrated waveguide-substrate integrated waveguide is studied.Under the requirements of corresponding indicators,the electromagnetic leakage problems of the transition coaxial and coaxial-like in the microstrip-microstrip vertical transition structure are analyzed.The results show that the coaxial-like structure can effectively prevent electromagnetic leakage;The transition structure was verified by the arrangement of the double-row metallized grounding holes and the "triangular position" relationship of the multilayer board under the misalignment.The results show that it is also suitable for the microstrip transmission line transition structure of the multilayer board.The far-end crosstalk of the substrate-integratedwaveguide-substrate-integrated waveguide adjacent structure is studied,and the improved SIW structure is used to verify the previous conclusion.The results show that the SIW-SIW transition structure is coupled without adding protection.The value is already better than 50 d B.The joint model after adding the substrate integrated waveguide-microstrip conversion structure and the microstrip-waveguide probe structure is analyzed.The results show that the insertion loss is changed from the original 1d B to 3d B,and the return loss value is in the corresponding frequency band Still better than 20 d B. |
