Energy Storage Effect in MSSW Metal-Finger Reflectors

Experimental results are presented on the magnetostatic-surface wave (MSSW) scattering properties of a grating of metal fingers placed at a variable height above the YIG film and compared with theory. The agreement with theory is excellent if one takes into account energy storage at the metal-finger edges and if the width of the metal fingers is larger than the YIG-film thickness. It is concluded that, for smaller finger widths, the interaction between the edges of a metal finger must additionally be incorporated into the theory. The present results are significantly different from those for the scattering of magnetostatic forward volume waves (MSFVW´s) by a grating of metal fingers. In the latter case, the scattered modes are propagating MSFVW´s so that the problem of interaction between the edges of metal fingers is not present, i.e., the theory is valid for all widths of the metal fingers.