Читать книгу Introduction To Modern Planar Transmission Lines - Anand K. Verma - Страница 52

If the medium between two conductors of the transmission line is not a perfect dielectric, i.e. if it has finite conductivity, then a part of the line current shunts through the medium causing the dielectric loss. The dielectric loss of the line is modeled by shunt conductance G p.u.l. The instantaneous shunt current is related to the instantaneous voltage across a lumped conductance by

(2.1.15)

Figure (2.6a) shows a physical transmission line that supports the TEM mode wave propagation. Figure (2.6b) shows that this line could be modeled as a chain of the lumped RLCG structure. More numbers of RLCG sections per wavelength are needed to model a transmission line. The RLCG model is the modeling of a transmission line by the lossy series inductor and lossy shunt capacitor. The transmission line supports the wave propagation from power AC to RF and above. Likewise, the corresponding lumped components model of a transmission line also supports such waves. The transmission line structure behaves like a low‐pass filter.