I have been reading up on studies of magnetically tunable surface acoustic wave devices, in general they note the relative velocity change or in some cases a frequency shift if it is part of an oscillator or a resonator design.
These relative velocity changes are small, the upper values I have seen are 0.6% for a delay line structure and I believe I saw 1.2% frequency shift for a monolith resonator structure.
My understanding is that these changes are typically too small for useful practical applications within mobile communication systems, where a number of different frequency bands and communication protocols need to be supported.
However these could be used in other systems where a modest degree of adjustment is required or for magnetic or current sensing applications. I am curious as to whether these types of devices are used and produced commercially or whether this is primarily in the scope of academic research at this time.
And what are the minimal tuning ranges that would be required for practical and useful tunable filters and oscillators for mobile communication devices?