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US5319326A
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Surface-wave-type reflective delay line
Assignee: TDK Electronics AG
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Filing: 1992-04-08
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Granted: 1994-06-07
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Expires: 2012-04-08
Abstract
Abstract A surface-wave-type reflective delay line includes an input/output interdigital converter, and a plurality of surface wave reflectors. The surface wave reflectors are disposed at positions corresponding to an order of magnitude of half of a particular desired transit time of a surface wave between the input/output interdigital converter and an applicable surface wave reflector and back. At least some of the surface wave reflectors are each shifted by a mathematically random value out of the positions corresponding to half the particular desired transit time.
Inventors
- 👤 Bernd Fleischmann
- 👤 Peter Zibis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 12:58
CPC Classifications
H; H03; H03H; H03H9/00; H03H9/02; H03H9/02535; H03H9/02818; H03H9/02842; H03H9/0285; H03H9/30; H03H9/42
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
118 words
A surface-wave-type reflective delay line, comprising: a piezoelectric substrate, an input/output interdigital converter disposed on said substrate, and a plurality of surface wave reflectors disposed on said substrate, said surface wave reflectors disposed at nominal positions each having a distance from said input/output interdigital converter equal to a multiple of a half wavelength of an acoustic wave on said substrate, wherein said multiple is a positive integer, and at least one of said surface wave reflectors is shifted a shift distance equal to a random value from the nominal positions, wherein said random value of said shift distance of said surface wave reflectors is between -λ/4 and +λ/4, wherein λ represents the acoustical wavelength of the surface waves.
Claim 2
Dependent Claim
118 words
A surface-wave-type reflective delay line, comprising: a piezoelectric substrate, an input/output interdigital converter disposed on said substrate, and a plurality of surface wave reflectors disposed on said substrate, said surface wave reflectors disposed at nominal positions each having a distance from said input/output interdigital converter equal to a multiple of a half wavelength of an acoustic wave on said substrate, wherein said multiple is a positive integer, and at least one of said surface wave reflectors is shifted a shift distance equal to a random value from the nominal positions, wherein said random value of said shift distance of said surface wave reflectors is between -λ/4 and +λ/4, wherein λ represents the acoustical wavelength of the surface waves.
Claim 3
Dependent Claim
83 words
The delay line according to claim 1, wherein: said surface wave reflectors include reflecting and non-reflecting reflector structures for attaining a predetermined bit code in an output pulse train at said input/output interdigital converter, said reflecting reflector structures correspond to a first logic level and said non-reflecting reflector structures correspond to a second logic level, and every other reflecting reflector structure is shifted by λ/4 from the position corresponding to the respective half transit time toward or away from said input/output interdigital converter.
Claim 4
Dependent Claim
84 words
The delay line according to claim 1, wherein: said surface wave reflectors include reflecting and non-reflecting reflector structures for attaining a predetermined bit code in an output pulse train at said input/output interdigital converter, said reflecting reflector structures correspond to a first logic level and said non-reflecting reflector structures correspond to a second logic level, and every other reflecting reflector structure is shifted by λ/8 away from the nominal position corresponding to the respective half wavelength toward or away from said input/output interdigital converter.
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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) | 1997-06-06 | 1997-12-06 | 1998-06-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-06 | 2001-12-06 | 2002-06-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-06 | 2005-12-06 | 2006-06-07 | $7700.00 | Window Closed / Lapsed |