Acoustic surface-wave filter
AssigneeLicentia Patent-Verwaltungs-G.m.b.H.
InventorsManfred Borner, Gerhard Kohlbacher
Life of this patent
Estimating the term…
Abstract
An acoustic surface-wave filter comprises an element which is excitable to perform surface oscillations, which is formed at least partly of piezoelectric material and has interference locations for the surface wave on its surface together with electromechanical converter means, at least some of the interference locations forming a resonator with the average spacing of the interference locations being equal to a half of the wavelength of the surface waves or a whole number multiple of a half of the wavelength of the surface waves.
Claims34
In an acoustic surface-wave filter comprising at least one element excitable to perform surface oscillations, at least partly of piezoelectric material and defining a surface, on at least one side thereof, with interference locations for surface waves, input transducer means for converting electrical energy into mechanical energy and output transducer means for converting mechanical energy into electrical energy, the improvement wherein at least some said interference locations are oireinted perpendicular to the original direction of propagation of an excited acoustic surface wave, are disposed between said input and output transducer means in the path of propagation of an excited acoustic surface-wave, and are combined into a resonator in the form of a ruled grating with the average distance between said interference locations in said resonator being equal to half the wavelength of the surface-waves or a whole-number multiple of a half of the wavelength of the surface-waves.
An acoustic surface-wave filter comprising an element excitable to perform surface oscillations, said element being at least partly formed of piezoelectric material and defining a surface on one side thereof;
- interference locations for surface-waves on said surface defined by said element, said interference locations each having dimensions in the direction of propagation of the surface-wave;
- input transducer means on said element for converting electrical energy into mechanical energy;
- output transducer means on said element for converting mechanical energy into electrical energy;
- and a resonator disposed between said input and output transducer means and in the direction of propagation of an excited acoustic surface wave, said resonator including a line grating formed by at least some of said interference locations which are oriented perpendicular to the original direction of propagation of an excited acoustic surface-wave and which have an average spacing equal to half the wavelength of the surface-waves or a whole number multiple of a half of the wavelength of the surface-waves.
Dependencies are inferred from the claim text.