P5H-3 A COM Analysis of SAW Tags Operating at Harmonic Frequencies

Abstract

The operation of surface acoustic wave (SAW) tags at harmonic modes can relax lithography restriction from the frequency raise and archive a good power handling. In this paper a simulation tool for analyzing SAW tags operating at harmonic frequencies is developed. We extended a coupling of modes (COM) model to calculate their harmonic responses by integrating the quasi-static approximation. The considered SAW tags were decimal and had reflectors of single-electrode IDT, three-finger IDT and split-electrode IDT. Finally, some related experiments were implemented: the SAW tags were by micro-electro-mechanical system processes and measured via Network analyzer and a probe station. Experimental results, showing a good agreement with simulation results, prove the feasibility of the proposed simulation tool. Based on all results, we found that the 2nd harmonic of three-finger IDT and 3rd harmonic of split-electrode IDT are effective to achieve a higher operating frequency for SAW tags.