Energy Transport Theorem (ETT)-Based Decoupling Mode Theory (DMT) for the Wave-Port-Fed Receiving Antennas

The energy transport mechanism of the wave-port-fed antenna-receiving problem is analyzed. The energy transport theorem (ETT) used to quantitatively govern the energy transport process is derived. The input power operator (IPO, which is the source for sustaining the energy transport) is formulated. The dependent variable elimination (DVE) scheme for eliminating the dependent currents contained in the IPO is proposed. The diagonalizing IPO method for calculating the energy-decoupled modes (E-DMs) of the wave-port-fed objective receiving antenna is established. In any integral period, the obtained E-DMs do not have net energy exchange during the process of propagating towards to the receiving antenna. The E-DMs-based modal expansion is discussed, and the corresponding Parseval's theorem is derived. The Parseval's theorem implies that: for a physically realizable antenna-receiving mode (not restricted to the E-DMs), its time-domain energy, frequency-domain energy, and spectrum-domain energy are the same. Some important modal quantities used to quantitatively depict the modal energy utilization features are also discussed, such as the modal input impedance, modal input admittance, modal generalized quality-factor, and modal significance.