Experimental techniques in measuring ferrite line widths with a cross-guide coupler

Experimental results are presented to show the effect on the line width of the sample size and the surface finish of a YIG sphere measured in a cross-guide coupler. With this method, a 3:1 variation in sample size caused a 5-percent change in the line width, while an improvement in the surface finish caused a 25-percent reduction in the line width. Preliminary experimental data also indicated that there was no variation in the line width as a function of frequency from 2.6 - 18.0 KMC, but that the measured line width at 35 KMC was twice as large.