Finite element analysis on impedance matching layer thickness

A 0-3 alumina-HYSOL epoxy composite was made with the volume fraction of alumina varied from 0 to 40% and the physical properties were measured. These properties were used as input values for the matching layer properties in a finite element model of a 5 MHz PZT-5H transducer. The thickness of the matching layer was varied and corresponding transmitted power into the water was calculated and compared to that of the quarter wave length thickness matching. The optimum matching layer thickness for this model was found to be 11% less than /spl lambda//4.