The temperature coefficient of frequency and quality factors at resonance and antiresonance frequencies of infinite interdigital transducers for leaky surface acoustic waves on a SiO2/IDT/36° Y-X LiTaO3 substrate

The temperature coefficient, electromechanical coupling coefficient and quality factors at resonance frequencies of infinite interdigital transducers (IDTs) for leaky or nonleaky surface acoustic waves on SiO2/IDT/36degrees Y-X LiTaO3 are presented. The electrode materials of IDTs with aluminum, copper, gold, silver, tantalum, titanium or tungsten alloy are examined. Using the hybrid Trefftz finite element method, the radiation conditions of leaky surface acoutic waves are rigorously taken into account in the presented results. Computed values reveal that silver electrode IDTs with a SiO2 film thickness of 0.36p and an electrode height of 0.2p have an electromechanical coupling coefficient of 0.035 and a temperature coefficient of frequency of -10 ppm/degreesC, where p is the period of IDT fingers.