A surface acoustic wave tag device is disclosed, comprising: an acoustic wave propagating substrate, at least one transducer structure comprising inter-digitated comb electrodes, and at least one reflecting means, the reflecting means comprising at least one reflector, wherein the acoustic wave propagation substrate is a composite substrate comprising a base substrate and a piezoelectric layer, wherein the crystallographic orientation of the piezoelectric layer with respect to the base substrate is such that the propagation of a shear wave inside the piezoelectric layer and in the direction of propagation corresponding to the acoustic wave is enabled. A physical quantity determining device and a fabrication method of such surface acoustic wave tag device are also disclosed.