Caractéristiques des ondes se propageant dans des structures périodiques a ondes lentes en technologie microélectronique

A study is made of the charge and potential at every point in the cross section of an elementary cell of a microstrip delay line. By solving a first order Fredholm integral equation in the complex plane, the charge density of the two conductors in the elementary cell is determined. This value is used to obtain the fundamental propagation modes, the characteristic impedance, the phase velocity, and the effective dielectric constant. An evaluation of parameter variations and line geometry yields general coupling laws. Relating these boundary conditions to individual structures, dispersion diagrams and iterative impedance are found. Besides the classic meander line, the interdigital line of structures composed of many dielectric layers has been studied.