If I have a 20 MHz surface wave travelling along a material, and then introduce a 50 or 100 Hz wave source, will there be a noticeable difference to the output?
(Surface acoustic wave type device, for generating and detecting the waves, lower frequency wave with other mechanism)
If the surface wave velocity is 4 km/s, the 20 MHz has a wavelength of 200 um and a 100 Hz wavelength would be 40 m. So would I be right in thinking that these are not really comparable? And a set up to measure 20 MHz would not detect a surface wave with such a low frequency and no change would be detected in the output?
Thanks for any help.