Advanced 2D periodic array and full transversal mode suppression

• Published in: 2013 IEEE International Ultrasonics Symposium (IUS) pp. 733 - 736
• Main Authors: Jiman Yoon, Mayer, Markus, Ebner, Thomas, Wagner, Karl, Wixforth, Achim
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.07.2013
• Subjects: Arrays; Electrodes; Full Transversal Mode Suppression; Geometry; Periodic Array; Resonant frequency; SAW; Surface acoustic waves; Waveguide
• ISSN: 1051-0117
• DOI: 10.1109/ULTSYM.2013.0189

In this work, we present an improved version of the 2D periodic array from [Yoon et al, IUS2012, [1]]. Using a 2D P-matrix simulation tool, required COM (coupling of modes) parameters and periodic Δv/v waveguide parameters were optimized for desired 2D behavior. On this basis, the fine-tuned real geometries were determined. In the analysis of such a resonator, we introduce a novel approach in analogy to a multiple quantum well structure in solid state physics. It turns out that the optimized 2D periodic array with geometry variations fully suppresses all unwanted transversal modes within a certain bandwidth. Besides, prominent peaks by the transversal periodicity are also distinctively suppressed at the frequencies where the wavelength of the y-components of the transversal modes is comparable to the transversal pitch (p T ), i.e., near k v =π/p T . Therefore the 2D periodic array on the electrodes can be readily employed in designing SAW filters in SiO 2 -covered LiNbO 3 with excellent performance.