Surface acoustic wave device with impedance matching network formed thereon
First Claim
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1. A surface acoustic wave device which comprises:
- a piezoelectric substrate which includes a semiconductor substrate and a piezoelectric film deposited on said semiconductor substrate, said semiconductor substrate including means defining a low resistance zone along a surface thereof having said piezoelectric film thereon;
transducer means provided on said piezoelectric substrate;
at least one pair of rectangular patterns of conductive film provided on said piezoelectric film and connected to said transducer means, said rectangular patterns being aligned with said low resistance zone; and
strip lines of conductive film provided on said piezoelectric film and each having an end which is connected to a respective one of said rectangular patterns, said strip lines being aligned with said low resistance zone;
said piezoelectric substrate, said low resistance zone, said rectangular patterns and said strip lines serving as a matching circuit which matches the electrical admittance of said surface acoustic wave device with the electrical admittance of an external circuit to be connected to ends of said strip lines remote from said rectangular patterns.
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Abstract
The surface acoustic wave device comprises an elastic substrate, a piezoelectric film deposited on the elastic substrate, and transducers and matching circuits both provided on the piezoelectric film or along the interface between the piezoelectric film and the elastic substrate.
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Citations
10 Claims
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1. A surface acoustic wave device which comprises:
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a piezoelectric substrate which includes a semiconductor substrate and a piezoelectric film deposited on said semiconductor substrate, said semiconductor substrate including means defining a low resistance zone along a surface thereof having said piezoelectric film thereon; transducer means provided on said piezoelectric substrate; at least one pair of rectangular patterns of conductive film provided on said piezoelectric film and connected to said transducer means, said rectangular patterns being aligned with said low resistance zone; and strip lines of conductive film provided on said piezoelectric film and each having an end which is connected to a respective one of said rectangular patterns, said strip lines being aligned with said low resistance zone; said piezoelectric substrate, said low resistance zone, said rectangular patterns and said strip lines serving as a matching circuit which matches the electrical admittance of said surface acoustic wave device with the electrical admittance of an external circuit to be connected to ends of said strip lines remote from said rectangular patterns. - View Dependent Claims (2)
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3. A surface acoustic wave device, comprising:
- a piezoelectric substrate;
transducer means provided on said piezoelectric substrate;
first and second sections of conductive film which are generally rectangular, are provided on said piezoelectric substrate, and are electrically connected to said transducer means; and
first and second strip lines which are provided on said piezoelectric substrate and which each have an end connected to a respective one of said first and second sections of conductive film;
said piezoelectric substrate, said first and second sections and said strip lines serving as a matching circuit which matches the electrical admittance of said surface acoustic wave device to the electrical admittance of an external circuit to be connected to ends of said strip lines remote from said first and second sections of conductive film;
wherein said piezoelectric substrate includes a semiconductor substrate and a piezoelectric film deposited thereon, wherein said transducer means, said first and second sections of conductive film and said strip lines are provided on a side of said piezoelectric film remote from said semiconductor substrate, and wherein said semiconductor substrate includes means defining a low resistance zone adjacent said piezoelectric film and aligned with said strip lines and said first and second sections of conductive film. - View Dependent Claims (4, 5, 6, 7)
- a piezoelectric substrate;
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8. A surface acoustic wave device which comprises:
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a piezoelectric substrate which includes a semiconductor substrate, an insulative film deposited on said semiconductor substrate, and a piezoelectric film deposited on said insulative film; transducer means provided on said insulative film; at least one pair of rectangular patterns of conductive film provided on said insulative film and connected to said transducer means; and strip lines of conductive film provided on said insulative film and each having an end which is connected to a respective one of said rectangular patterns; said substrate, said rectangular patterns and said strip lines serving as a matching circuit which matches the electrical admittance of said surface acoustic wave device with the electrical admittance of an external circuit to be connected to ends of said strip lines remote from said rectangular patterns, said semiconductor substrate including a low resistance zone along a surface thereof having said insulative film thereon.
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9. A surface acoustic wave device, comprising:
- a piezoelectric substrate;
transducer means provided on said piezoelectric substrate;
first and second sections of conductive film which are generally rectangular, are provided on said piezoelectric substrate, and are electrically connected to said transducer means; and
first and second strip lines which are provided on said piezoelectric substrate and which each have an end connected to a respective one of said first and second sections of conductive film;
said piezoelectric substrate, said first and second sections and said strip lines serving as a matching circuit which matches the electrical admittance of said surface acoustic wave device to the electrical admittance of an external circuit to be connected to ends of said strip lines remote from said first and second sections of conductive film;
wherein said piezoelectric substrate includes a semiconductor substrate, an insulative film, and a piezoelectric film, said insulative film being provided between said piezoelectric film and said semiconductor substrate, wherein said transducer means, said first and second sections of conductive film and said strip lines are provided on a side of said insulative film adjacent said piezoelectric film, and wherein said semiconductor substrate including means defining a low resistance zone which is adjacent said insulative film and aligned with said first and second sections of conductive film. - View Dependent Claims (10)
- a piezoelectric substrate;
Specification