Magnetically tuned surface-acoustic-wave phase shifter

A novel technique for achieving variable phase shift in surface-acoustic-wave devices is demonstrated. By depositing a thin film of magnetostrictive material onto the surface of a conventional surface-acoustic-wave delay line, the wave velocity can be varied by adjusting an externally applied magnetic field. Experimental results are presented for a nickel film on a lithium-niobate substrate, and several possible applications are mentioned.