Читать книгу Introduction To Modern Planar Transmission Lines - Anand K. Verma - Страница 210

The obliquely incident plane wave is partly reflected and partly transmitted at the interface of two electrically dissimilar media. It helps to think the medium #1 and medium #2 as two dissimilar transmission lines with a junction PQ, corresponding to the interface PQ as shown in Figs (5.2a) and (5.3a) for the TE and TM polarization, respectively. Figures (5.2b) and (5.3b) show the equivalent transmission line networks of the composite media, supporting the oblique incidence of the TE and TM‐polarized plane waves. The source connected to the line #1, with characteristic impedance Z₀, corresponding to the wave impedance of the incident wave in medium #1, is assumed to be located at the left of the junction. The line #2 is of an infinite extent that offers a load Z_L, corresponding to the wave impedance of the transmitted (refracted) wave in medium #2, at the junction. The reflection and transmission coefficients of the incident wave at the physical media interface correspond to the mismatch, causing reflection and transmission, at the junction of two equivalent lines. Our task is to determine the Z₀ and Z_L in terms of the wave impedances of medium #1 and medium #2, respectively, for both the TE and TM polarizations. The correlation between the reflection/transmission coefficient of the TE and TM‐polarized waves at the interface of physical media and reflection/transmission coefficient at the junction of equivalent lines is also be considered.