Magnetostatic Mode Excitation in YIG Rods Containing a Turning Point

Calculations have been made of the (1, 0) magnetostatic mode excitation in an axially magnetized YIG rod containing a turning point. The rf-field components have been determined within the magnetostatic approximation from the wave equation of the magnetic potential. The nonuniformity of the bias field was taken into account and the boundary conditions were specified at the end face of the rod where the excitation source, taken as a circular loop, was assumed to be situated. An expression for the power absorbed under these conditions was derived. Numerical results have been obtained by means of an electronic computer, taking the bias field and the frequency as parameters. Experimental measurements of the power absorbed by a YIG single-crystal rod were performed in S band, showing a good agreement with the theoretical expectation. Measurements of the losses of an optimized delayed signal are also reported for the magnetoelastic mode of operation. It is shown that the variation of these losses can be attributed for a great part to that of the conversion efficiency of the magnetostatic mode.