Patent ID: 8907769

Claim:
A surface acoustic wave device responsive to an interrogation signal for producing a return signal, the surface acoustic wave device comprising: an antenna for receiving the interrogation signal; a piezoelectric substrate; one or more frequency-selective reflective arrays disposed on the piezoelectric substrate; an interdigital transducer for launching an incident surface acoustic wave on the substrate in response to the interrogation signal, the incident surface acoustic wave propagating to the one or more frequency-selective reflective arrays; a reflected surface acoustic wave reflected from each one of the reflective arrays; the interdigital transducer receiving the reflected surface acoustic waves; the return signal, responsive to each reflected surface acoustic waves; wherein a frequency difference Δf between a frequency of the reflected surface acoustic wave reflected from a first frequency-selective reflective array and the reflected surface acoustic wave reflected from a second reflective array is selected to minimize amplitude ripple in a power spectrum of the return signal; wherein the frequency difference Δf is selected such that the power spectra of the reflected surface acoustic wave from each of the frequency-selective reflective arrays overlap at a frequency at about a half power value.