多層基板で直交する異層線路間での妨害結合におけるモデル化と解析手法に関する研究

摘要

In this thesis, main target has been to obtain a novel circuit model for the couplingbetween two orthogonally intersecting strip conductors in configuration of strip line and/ormicrostrip line on different layers. Such circuit models would make it easy to understandthe coupling mechanism, and then one might avoid time-consuming works to estimate inadvance the coupling of high-risk probability in various configurations in real products.First, we have proposed a circuit model for discussing the crosstalk problem betweendouble strip lines model and double microstrip lines model crossing orthogonally and verifiedthe effective of the proposed model. The proposed model is based on telegrapher’sequations for the coupling of external fields to a transmission line. Coupling betweencrossing lines are caused by the electric field in a field concept and mutual capacitance in acircuit concept. Instead of obtaining the electric field, the scalar potential for strip line andmicrostrip line is approximated by using an electric image method. Taking account of thefields caused by the lines in terms of line voltages and currents at the line end terminals,we have proposed a novel four-port circuit network model, an ABCD matrix expression, inthe frequency-domain. In three different geometries, strip lines, embedded microstrip lines,and embedded-and-surface microstrip lines, we have confirmed the proposed approachesby comparing the results of the experiment and the calculation, which were in the goodagreement.Next, a lumped circuit model has been proposed for assessing the crosstalk between twostrip lines, embedded microstrip lines, and embedded-and-surface microstrip lines whichare intersecting orthogonally. Additionally, we have proposed two determination methods for the equivalent lumped capacitance by estimating a proposed error estimate and by estimatingphysical dimension of line systems. The proposed modeling approach was comparedto experimental results with good agreement. Furthermore, the analysis time was dramaticallydecreased by using the proposed method compared with one by using a 3-dimentionalfull wave analysis. The crosstalk between orthogonally intersecting lines is dominated bythe electric field, and is represented by a mutual capacitance in a circuit concept. Themutual capacitance is distributed near the intersecting point, so it can be modeled as alumped mutual capacitance. To estimate the lumped mutual capacitance, the total distributedmutual capacitance was placed at the intersection of the two orthogonal strip linesor microstrip lines. And in these evaluation models, the optimal phase progressions of thepropagating voltage wave on the transmission line of strip line model, embedded microstripline model and embedded-and-surface microstrip line model have been clear around ±40from the intersecting point. Moreover, we verify the circuit model for geometry of consumerproducts and we have made the design curves of equivalent mutual lumped capacitances.Additionally, we have discussed circuit models in the time-domain for the interferencecoupling between orthogonally intersecting two strip lines sandwiched by two referenceplanes. The circuit model proposed here was for making an inverse Laplace transform easy.The interference coupling in the time-domain was obtained in an analytical expression. Weverified the proposed models by comparing the time-domain results of the experiment withthose of the calculation, which were in good agreements.Finally, the coupling between two transmission lines intersecting in an arbitrary directionon different layers has been studied. In this thesis, the theory is developed on the assumptionthat transmission-line parameters, such as characteristic impedance and propagationconstant, correspond to those of isolated lines. In the transmission-line model for stripsintersecting at non-right angles, there is magnetic-field coupling in addition to the electric-fieldcoupling discussed previously. The magnetic-field generated from an infinite-lengthline can be derived from the vector magnetic potential. Then, the linking magnetic flux,which is the coupling-source component, can be estimated. Thus, the mutual inductanceand capacitance distributed along the lines can be formulated. By checking the distributionprofile, a circuit in terms of equivalent lumped inductance and capacitance elements wasproposed.