Energy Transport Theorem (ETT)-Based Decoupling Mode Theory (DMT) for Microstrip Transmission Lines and Power Dividers

An energy-viewpoint-based electromagnetic modal analysis method—decoupling mode theory (DMT)—is proposed for microstrip transmission lines. The DMT is established using energy transport theorem (ETT) framework. The ETT-based DMT (ETT-DMT) can use diagonalizing input power operator (IPO) method to construct a set of energy-decoupled fundamental working modes [simply called energy-decoupled modes (DMs)] for an objective microstrip transmission line. The DMs can effectively reveal the inherent energy transmission character of the objective microstrip transmission line, and any two different DMs do not have net energy exchange in an integral period. Besides microstrip transmission lines, the ETT-DMT is also applicable to microstrip power dividers. By some proper generalizations, the ETT-DMT can also be applied to SMA-microstrip-SMA transmission-line and power-divider systems.