The interaction between magnetostatic waves (MSWs) and surface acoustic waves (SAWs) propagating in the same epitaxially grown single-crystal yttrium iron garnet (YIG) film is investigated. As the acoustic wave propagates in the magnetic film, magnetoelastic coupling between the elastic strain fields of the SAW and the magnetic spin system takes place, so that the SAW slightly modulates the characteristics of the magnetic medium. A novel approach for spectrum analysis is introduced that is based on the diffraction of a magnetostatic wave by a Bragg cell generated by an acoustic wave. The RF signal to be detected is fed to a single microstrip line to excite the MSW. Thus, the operating frequency of such a device can be as high as 20 GHz or more. >