Surface acoustic wave filter
First Claim
Patent Images
1. A surface acoustic wave filter having an input end and an output end, said filter comprising:
- a piezoelectric substrate;
a plurality of interdigital transducers located on said piezoelectric substrate and arranged along a surface wave propagation direction in a surface wave propagating region, said plurality of interdigital transducers forming a surface acoustic wave filter part having a pass band and having input and output sides directly coupled to said input and output ends of said surface acoustic wave filter, respectively; and
a one-port SAW resonator, having at least one interdigital transducer and being connected at least between one of said input and output sides of said surface acoustic wave filter part and a ground potential, said one-port SAW resonator being located in a region of the piezoelectric substrate other than said surface wave propagating region,a resonance frequency of said one-port SAW resonator being set at a frequency region lower than the pass band of said surface acoustic wave filter part.
0 Assignments
0 Petitions
Accused Products
Abstract
A surface acoustic wave (SAW) filter includes a plurality of interdigital transducers located on a piezoelectric substrate along a surface wave propagation direction, at least a single one-port SAW resonator being connected in parallel with an output side of the SAW filter, while the resonance frequency (f0) of the SAW resonator is set in frequency region level which is lower than the pass band of the SAW filter.
-
Citations
10 Claims
-
1. A surface acoustic wave filter having an input end and an output end, said filter comprising:
-
a piezoelectric substrate; a plurality of interdigital transducers located on said piezoelectric substrate and arranged along a surface wave propagation direction in a surface wave propagating region, said plurality of interdigital transducers forming a surface acoustic wave filter part having a pass band and having input and output sides directly coupled to said input and output ends of said surface acoustic wave filter, respectively; and a one-port SAW resonator, having at least one interdigital transducer and being connected at least between one of said input and output sides of said surface acoustic wave filter part and a ground potential, said one-port SAW resonator being located in a region of the piezoelectric substrate other than said surface wave propagating region, a resonance frequency of said one-port SAW resonator being set at a frequency region lower than the pass band of said surface acoustic wave filter part. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
Specification