Patent US5073763A successfully refreshed from Google Patents.
US5073763A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Group single-phase unidirectional transducers with 3/8λand 5/8λ sampling
Assignee: RF Monolithics Inc
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Filing: 1990-11-02
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Granted: 1991-12-17
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Expires: 2010-11-02
Abstract
Abstract Novel GSPUDT structures are disclosed with 3/8λ and 5/8λ group sampling with 3λ and 5λ group responses. Reflectionless or unidirectional transducers, and broadband notch elements are all implementable with these new configurations. These GSPUDTs are similar to the conventional SPUDT and the "Hopscotch" transducers in that single level versions are reflectionless. Unidirectional characteristics are only obtainable from a two-level structure.
Inventors
- 👤 Peter Wright
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 22:18
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14502; H03H9/14505; H03H9/14517; H03H9/1452; H03H9/14526; H03H9/14538; H03H9/14544; H03H9/14552
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
44 words
An improved surface acoustic wave transducer comprising: a pattern of at least three adjacent interdigitated electrodes on a piezoelectric substrate; and each of said interdigitated electrodes lying on a 3/8λ grid such that adjacent electrodes have a center-to-center spacing of 3/8λ where λ=one wavelength.
Claim 2
Dependent Claim
44 words
An improved surface acoustic wave transducer comprising: a pattern of at least three adjacent interdigitated electrodes on a piezoelectric substrate; and each of said interdigitated electrodes lying on a 3/8λ grid such that adjacent electrodes have a center-to-center spacing of 3/8λ where λ=one wavelength.
Claim 3
Dependent Claim
22 words
An improved surface acoustic wave transducer as in claim 1 wherein said electrodes are selectively weighted to obtain a desired transduction characteristic.
Claim 4
Dependent Claim
21 words
An improved surface acoustic wave transducer as in claim 2 wherein said weighting to obtain a desired transduction is withdrawal weighting.
Claim 5
Dependent Claim
22 words
An improved surface acoustic wave transducer as in claim 2 wherein said weighting to obtain a desired transduction characteristic is overlap weighting.
Claim 6
Dependent Claim
26 words
An improved surface acoustic wave transducer as in claim 1 wherein said electrodes are selectively weighted with additional overlay material to obtain a desired reflectivity characteristic.
Claim 7
Dependent Claim
21 words
An improved surface acoustic wave transducer as in claim 5 wherein said weighting to obtain a desired reflectivity is analogue weighting.
Claim 8
Dependent Claim
44 words
An improved surface acoustic wave transducer comprising: a pattern of at least three adjacent interdigitated electrodes on a piezoelectric substrate; and each of said interdigitated electrodes lying on a 5/8λ grid such that adjacent electrodes have a center-to-center spacing on 5/8λ where λ=one wavelength.
Claim 9
Dependent Claim
44 words
An improved surface acoustic wave transducer comprising: a pattern of at least three adjacent interdigitated electrodes on a piezoelectric substrate; and each of said interdigitated electrodes lying on a 5/8λ grid such that adjacent electrodes have a center-to-center spacing on 5/8λ where λ=one wavelength.
Claim 10
Dependent Claim
22 words
An improved surface acoustic wave transducer as in claim 7 wherein said electrodes are selectively weighted to obtain a desired transduction characteristic.
Claim 11
Dependent Claim
21 words
An improved surface acoustic wave transducer as in claim 8 wherein said weighting to obtain a desired transduction is withdrawal weighting.
Claim 12
Dependent Claim
22 words
An improved surface acoustic wave transducer as in claim 8 wherein said weighting to obtain a desired transduction characteristic is overlap weighting.
Claim 13
Dependent Claim
26 words
An improved surface acoustic wave transducer as in claim 7 wherein said electrodes are selectively weighted with additional overlay material to obtain a desired reflectivity characteristic.
Claim 14
Dependent Claim
21 words
An improved surface acoustic wave transducer as in claim 11 wherein said weighting to obtain a desired reflectivity is analogue weighting.
Claim 15
Dependent Claim
77 words
A surface acoustic wave transducer as in claim 1 wherein said pattern of interdigitated electrodes comprises: a plurality of first pairs of interdigitated electrodes, each said first pair of electrodes having reversed polarity from the preceding first pair; a plurality of second pairs of electrodes interdigitated with said plurality of first pairs of electrodes; and both electrodes in each second pair having a polarity opposite the polarity of the adjacent one of the first pair of electrodes.
Claim 16
Dependent Claim
77 words
A surface acoustic wave transducer as in claim 13 further comprising: mass loading on only one corresponding electrode of each of the second pair of electrodes and its adjacent first pair electrode to obtain unidirectional transmission in one direction in the substrate; and mass loading on only the corresponding other one electrode of each of the second pair of electrodes and its adjacent first pair electrode to obtain unidirectional transmission in the other direction in the substrate.
Claim 17
Dependent Claim
80 words
A surface acoustic wave transducer as in claim 13 further including: said interdigitated electrodes positioned on said substrate to establish centers of reflection and transduction in said substrate that are separated by ±45° or ±135°; mass loading on only each electrode in each pair of electrodes to obtain unidirectional transmission in one direction on the substrate; and mass loading on only each electrode in each second pair of electrodes to obtain unidirectional transmission in the reverse direction on the substrate.
Claim 18
Dependent Claim
77 words
A surface acoustic wave transducer as in claim 7 wherein said pattern of interdigitated electrodes comprises: a plurality of first pairs of interdigitated electrodes, each said first pair of electrodes having reversed polarity from the preceding first pair; a plurality of second pairs of electrodes interdigitated with said plurality of first pairs of electrodes; and both electrodes in each second pair having a polarity opposite the polarity of the adjacent one of the first pair of electrodes.
Claim 19
Dependent Claim
76 words
A surface acoustic wave transducer as in claim 16 further comprising: mass loading on only one corresponding electrode of each of the second pair of electrodes and its adjacent first pair electrode to obtain unidirectional transmission in one direction in the substrate; and mass loading on only the corresponding other electrode of each of the second pair of electrodes and its adjacent first pair electrode to obtain unidirectional transmission in the other direction in the substrate.
Claim 20
Dependent Claim
81 words
A surface acoustic wave transducer as in claim 16 further including: said interdigitated electrodes positioned on said substrate to establish centers of reflection and transduction in said substrate that are separated by ±45° or ±135°; mass loading on only each electrode in each first pair of electrodes to obtain unidirectional transmission in one direction on the substrate; and mass loading on only each electrode in each second pair of electrodes to obtain unidirectional transmission in the reverse direction on the substrate.
Claim 21
Dependent Claim
19 words
A surface acoustic wave transducer as in claim 1 wherein the pattern of electrodes repeats itself each three wavelengths.
Claim 22
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 19 wherein: each of said electrodes has a width of λ/4; and adjacent electrodes are separated by a gap of λ/8.
Claim 23
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 19 wherein: each of said electrodes has a width of λ/8; and adjacent electrodes are separated by a gap of λ/4.
Claim 24
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 19 wherein: each of said electrodes has a width of 3/16λ; and adjacent electrodes are separated by a gap of 3/16λ.
Claim 25
Dependent Claim
19 words
A surface acoustic wave transducer as in claim 7 wherein the pattern of electrodes repeats itself each five wavelengths.
Claim 26
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 23 wherein: each of said electrodes have a width of 3/8λ; and adjacent electrodes are separated by a gap of λ/4.
Claim 27
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 23 wherein: each of said electrodes has a width of λ/4 and; adjacent electrodes are separated by a gap of 3/8λ.
Claim 28
Dependent Claim
29 words
A surface acoustic wave transducer as in claim 23 wherein: each of said electrodes has a width of 5/16λ; and adjacent electrodes are separated by a gap of 5/16λ.
Claim 29
Dependent Claim
59 words
In a surface acoustic wave device of the type having input and output spaced aligned transducers on a crystal substrate, the improvement comprising: said transducers positioned on said substrate to establish centers of reflection and transduction in said substrate that are separated by ±45° or ±135°; and at lease one of said transducers being the transducer of claim 1.
Claim 30
Dependent Claim
31 words
In a surface acoustic wave device of the type having input and output spaced aligned transducers, the improvement comprising at least one of said transducers being the transducer of claim 1.
Claim 31
Dependent Claim
59 words
In a surface acoustic wave device of the type having input and output spaced aligned transducers on a crystal substrate, the improvement comprising: said transducers positioned on said substrate to establish centers of reflection and transduction in said substrate that are separated by ±45° or ±135°; and at least one of said transducers being the transducer of claim 7.
Claim 32
Dependent Claim
31 words
In a surface acoustic wave device of the type having input and output spaced aligned transducers, the improvement comprising at least one of said transducers being the transducer of claim 7.
Claim 33
Dependent Claim
59 words
In a surface acoustic wave filter of the type having input and output spaced aligned transducers, the improvement comprising: at least one of the transducers being the transducer of claim 1; and mass loading on predetermined ones of the electrodes of said at least one of said transducers so as to enable said transducers to communicate with each other.
Claim 34
Dependent Claim
59 words
In a surface acoustic wave filter of the type having input and output spaced aligned transducers, the improvement comprising: at least one of the transducers being the transducer of claim 7; and mass loading on predetermined ones of the electrodes of said at least one of said transducers so as to enable said transducers to communicate with each other.
Claim 35
Dependent Claim
86 words
In a surface acoustic wave filter of the type having input and output spaced aligned transducers on a crystal substrate, the improvement comprising: at least one of the transducers being the transducer of claim 1; the transducers positioned on the substrate to establish centers of reflection and transduction in the substrate that are separated by ±45° or ±135°; and mass loading on predetermined ones of the electrodes of said at least one of said transducers so as to enable said transducers to communicate with each other.
Claim 36
Dependent Claim
86 words
In a surface acoustic wave filter of the type having input and output spaced aligned transducers on a crystal substrate, the improvement comprising: at least one of the transducers being the transducer of claim 7; the transducers positioned on the substrate to establish centers of reflection and transduction in the substrate that are separated by ±45° or ±135°; and mass loading on predetermined ones of the electrodes of said at least one of said transducers so as to enable said transducers to communicate with each other.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-12-16 | 1995-06-17 | 1995-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-12-16 | 1999-06-17 | 1999-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-12-16 | 2003-06-17 | 2003-12-17 | $7700.00 | Window Closed / Lapsed |