Comparison of the grating and meander-line transducers for magnetoelastic surface-wave excitation

The grating transducer, the dual of the meander line, is studied and its performance compared with a meander line for the excitation of magnetoelastic surface waves. A LiNbO₃-YIG-LiNbO₃ epoxy-bonded composite is used to experimentally study both transducer geometries at 50 MHz. It is found that the grating transducer offers no significant improvement in performance over the meander line. Both types of transducers have large conversion losses because of large Ohmic resistance to radiation resistance ratios. Practical considerations of an allowable metalization thickness for the transducers and spatially nonuniform demagnetizing fields in the substrate permit only modest reductions in the conversion losses of either type of transducer situated on materials such as YIG.