In these cases,
weak coupling has been commonly assumed because of the low density of air and high stiffness of cabin wall, which means that the cavity's interior sound pressure would have little influence on the vibration of cavity wall, and modals of interior sound field would also be affected very lightly [5].
Contrary to, for example, a
weak coupling approximation, the pure dephasing model applied in this section is exact but for the price of credibility limited to the time scales which are short with respect to the time scales of energy dissipation [14].
1) are studied based on the coupled-mode formulation [29,30], which we have recently proposed using the first-order perturbation theory while taking into account a
weak coupling effect (mutual coupling coefficient is much smaller than the propagation constant in the single isolated PCW).
Similarly, it can be divided into three states as strong coupling,
weak coupling, and expansive coupling.
The presented model adopts a
weak coupling strategy when integrating the three modules for different physics.
For
weak coupling, the signal power for all dynamic variables decreases exponentially from low frequencies toward higher frequencies and distinctive energy peaks are not present for almost all variables.
[[??].sub.1] < [[gamma].sub.2]/[[gamma].sub.1] < 1/[[??].sub.2] for [[??].sub.1] < 1 [conjunction] [[??].sub.2] < 1 (
weak coupling).
The resonator characteristics of the proposed MMR are realized under
weak coupling.
The three resonant modes are observed under
weak coupling when feedline lengths are 0.5 mm and their magnitude arise with increment of feedline lengths from 0.5 mm to 2.1 mm.
Weak coupling can gain higher Q value, meanwhile,
weak coupling also reduce the incident power.