In Section 2 we have already discussed the effect of the finite film thickness and found that for SSDF films the efficient shielding disappears at a k = 200 rad/cm (Fig. 2b). In the case of transducer studies of travelling spin waves, the wave number range from 0 to 200 rad/cm represents a small portion of the full transmission characteristic accessible. The remainder of the range is expected to be that of a magnetic insulator. The smallness of the affected wavenumber range is the main reason why any evidence of the presence of the efficient microwave shielding is not significant in the travelling wave experiments with SSDF films. 

We can now understand the essential differences for typical broadband FMR experiments [1, 27]. The free spin wave propagation path depends on magnetic losses in the material and on the sample thickness. Film thickness are typically below 100 µ m, and the transducers are orders of magnitude larger (in our case the width of the microstrip is w =1.5 mm, and the width of the coplanar waveguide at w =0.35 mm, with Δ=0.6 mm). These systems therefore fall in the limiting broad case case k$_{max}$ << k$_{s}$ .Typically the transducer width is chosen such that it is smaller than the free spin-wave propagation path l$_{SW}$ = αω/V$_{g}$ in order to ensure a quasi-homogeneous microwave field in the film plane (here α is the Gilbert damping constant and V$_{g}$ is the spin wave group velocity). In this way the travelling spin wave contribution [2] to the absorption linewidth is minimized. However, for this geometry k$_{max}$ is virtually zero, so that eddy currents should have a major impact on the magnetization precession. Note that shielding cannot be observed directly, however as shown in [14], looking at exchange effects with broadband FMR allows one to determine clearly the presence of efficient eddy current screening. 

In conclusion, microwave magnetic dynamics in conducting films driven by wide stripline transducers is quite different from that observed in the traveling wave experiments and cavity FMR experiments on the sub magnetic skin depth films. Neither travelling wave experiments nor cavity FMR results are noticeably impacted by the eddy currents in the sample. For the traveling-wave experiments h$_{Oek}$ and h$_{prk}$ are negligible compared with h$_{dk}$ . For the cavity FMR, although h$_{Oek}$ and h$_{prk}$ are present and large, they are quasi-homogeneous across L and thus simply renormalise the homogeneous driving field. Furthermore, experiments on Brillouin light scattering on thermal magnons (see e.g. [38]) do not reveal any noticeable impact of the eddy currents either, as the only possible eddy current contribution to the total field of thermal magnons is h$_{prk}$ which has a negligible effect on magnon dispersion. 

