Abstract/Summary

It has been shown in part 1 of this work that absorption in film originates from wave cancelation theory (WCT) rather than the mechanism based on the attenuation power of material and impedance matching theory (IM). Although the attenuation power of the material and the amount of penetration are necessary factors to enable the film to absorb, and the pattern of the reflection loss curve is affected by the properties of the material, these factors affect multi-absorption peaks only via the mechanism of film. Whether the film has a metal back or not, maximum absorption always takes place when the two beams reflected from the two interfaces are out of phase by π at the front of the film, where maximum transmission from the film also occurs. The deviations of the maximum absorption positions of film from d = (2n+1)λ/4 or d = nλ/2 (d: film thickness, n: integer; and λ: wavelength within the film) can be readily understood from WCT which predicts that several broad peaks will usually occur. By contrast, IM only predicts the results correctly for specific cases such as resistive film, but generally provides inaccurate conclusions that only one sharp absorption peak will occur and that the amount of microwaves absorbed will be greater than the amount that penetrates.