Experimental and theoretical analysis of SAW properties of the langasite substrate with Euler angle (0/spl deg/,140/spl deg/,/spl phi/)

The numerical calculations using new material constants were in good agreement with the experimental results of the temperature-related SAW properties on the langasite substrate with Euler angle (0°,140°,φ). The temperature-related SAW properties as a function of the IDT metal thickness were also experimentally investigated. It was revealed that a thicker metal leads to a lower turnover temperature. Furthermore we investigated the NSPUDT (natural single phase unidirectional transducer) properties of langasite with Euler angle (0°,140°,25°) experimentally. Its directivity was almost equal to one estimated by the calculation based on the coupling of mode (COM) model. This NSPUDT property is a promising feature for the low-loss IF filter.