Patent US4499393A successfully refreshed from Google Patents.
US4499393A
Expired / Lapsed
US
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Surface acoustic wave spectrum analyzer
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1984-02-15
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Granted: 1985-02-12
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Expires: 2004-02-15
Abstract
Abstract A surface acoustic wave (SAW) device configured to operate as a spectrum analyzer, and having an array of input transducers disposed on a substrate in such positions as to produce a focused beam of acoustic energy at a focal arc, each position on the arc being representative of an input signal frequency. Output transducers produce electrical signals corresponding to the energy received at successive segments of the focal arc. The disclosed device includes various combinations of input transducer array improvements, some of which are to provide amplitude weighting of the input array, including aperture width weighting, capacitive weighting, resistive weighting, series-parallel weighting, and source withdrawal weighting. Another improvement in input array configuration eliminates close or overlapping electrodes of opposite polarities and thereby reduces parasitic capacitance and acoustic radiation between electrode elements. The use of curved input transducer fingers improves operation of the transducers as point sources. Other important improvements include the use of acoustic transducers before to transmit the focused output energy from the focal line to conventional output transducers, thereby improving frequency resolution, and the use of electromagnetic waveguides to transmit energy from output transducers located on the focal line.
Inventors
- 👤 Robert B. Stokes
- 👤 Kuo-Hsiung Yen
- 👤 Kei-Fung Lau
- 👤 Reynold S. Kagiwada
- 👤 Michael J. Delaney
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:58
CPC Classifications
G; G01; G01R; G01R23/00; G01R23/16; G01R23/17; H; H03; H03H; H03H9/00; H03H9/02; H03H9/125; H03H9/145; H03H9/14544; H03H9/1455
Claims Analysis
Total Claims: 49
Claim 1
Independent Claim
176 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer array is amplitude-weighted by means including series capacitance coupling of the input signals to selected ones of said input transducers.
Claim 2
Dependent Claim
176 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer array is amplitude-weighted by means including series capacitance coupling of the input signals to selected ones of said input transducers.
Claim 3
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 1, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 4
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 1, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 5
Dependent Claim
186 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc, each position on the focal arc of greater than zero order, laterally spaced from said axis of symmetry being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustical signals received at the focal arc into correponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer array is amplitude-weighted by means including means for selectively coupling said input transducers in series and parallel relationships to vary the amplitude of the resultant acoustic radiation across the array.
Claim 6
Dependent Claim
186 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc, each position on the focal arc of greater than zero order, laterally spaced from said axis of symmetry being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustical signals received at the focal arc into correponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer array is amplitude-weighted by means including means for selectively coupling said input transducers in series and parallel relationships to vary the amplitude of the resultant acoustic radiation across the array.
Claim 7
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 4, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 8
Dependent Claim
36 words
A surface acoustic waveguide as set forth in claim 4, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 9
Dependent Claim
170 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer is amplitude-weighted by selective removal of some of said input transducers from the array.
Claim 10
Dependent Claim
170 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducer is amplitude-weighted by selective removal of some of said input transducers from the array.
Claim 11
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 7, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 12
Dependent Claim
36 words
A surface acoustic waveguide as set forth in claim 7, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 13
Dependent Claim
38 words
A surface acoustic wave device as set forth in claim 4, wherein: said input transducer array is also amplitude-weighted by means of overlap weighting, wherein the degree of overlap of transducer fingers is selectively varied across the array.
Claim 14
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 10, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 15
Dependent Claim
38 words
A surface acoustic wave device as set forth in claim 7, wherein: said input transducer array is also amplitude-weighted by means of overlap weighting, wherein the degree of overlap of transducer fingers is selectively varied across the array.
Claim 16
Dependent Claim
36 words
A surface acoustic waveguide as set forth in claim 12, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 17
Dependent Claim
41 words
A surface acoustic wave device as set forth in claim 1, wherein: said input transducer array is also amplitude-weighted by means of resistive weighting, wherein selected ones of said input transducers have the input signals coupled to them through series resistors.
Claim 18
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 14, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 19
Dependent Claim
41 words
A surface acoustic wave device as set forth in claim 4, wherein: said input transducer array is also amplitude-weighted by means of resistive weighting, wherein selected ones of said input transducers have the input signals coupled to them through series resistors.
Claim 20
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 16, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 21
Dependent Claim
41 words
A surface acoustic wave device as set forth in claim 7, wherein: said input transducer array is also amplitude-weighted by means of resistive weighting, wherein selected ones of said input transducers have the input signals coupled to them through series resistors.
Claim 22
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 18, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 23
Dependent Claim
41 words
A surface acoustic wave device as set forth in claim 10, wherein: said input transducer array is also amplitude-weighted by means of resistive weighting, wherein selected ones of said input transducers have the input signals coupled to them through series resistors.
Claim 24
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 20, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 25
Dependent Claim
41 words
A surface acoustic wave device as set forth in claim 12, wherein: said input transducer array is also amplitude-weighted by means of resistive weighting, wherein selected ones of said input transducers have the input signals coupled to them through series resistors.
Claim 26
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 22, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 27
Dependent Claim
231 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically in parallel for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustical signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducers are formed by a pair of generally parallel electrodes, each having a plurality of sum bars extending between said electrodes in an interdigital fashion, each of said input transducers in said array having interdigitated fingers extending from a sum bar of one of said electrodes and a sum bar of the other electrode, each sum bar except end ones in said array providing transducer fingers for two adjacent ones of said input transducers.
Claim 28
Dependent Claim
231 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically in parallel for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustical signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducer array is amplitude-weighted to improve beam focusing and reduce beam sidelobes, and wherein said input transducers are formed by a pair of generally parallel electrodes, each having a plurality of sum bars extending between said electrodes in an interdigital fashion, each of said input transducers in said array having interdigitated fingers extending from a sum bar of one of said electrodes and a sum bar of the other electrode, each sum bar except end ones in said array providing transducer fingers for two adjacent ones of said input transducers.
Claim 29
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 24, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 30
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 24, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 31
Dependent Claim
162 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 32
Dependent Claim
162 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 33
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 27, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 34
Dependent Claim
171 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused at a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; an array of output transducers disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; and a plurality of acoustic waveguides leading from selected segments of the focal line to corresponding ones of said output transducers, whereby use of said waveguides provide for increased frequency resolution along the focal arc.
Claim 35
Dependent Claim
171 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused at a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; an array of output transducers disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; and a plurality of acoustic waveguides leading from selected segments of the focal line to corresponding ones of said output transducers, whereby use of said waveguides provide for increased frequency resolution along the focal arc.
Claim 36
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 29, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 37
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 29, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 38
Dependent Claim
38 words
A surface acoustic wave device as set forth in claim 29, wherein: said array of output transducers includes more than one transducer positioned to receive output signals from selected ones of said waveguides, for further improved frequency resolution.
Claim 39
Dependent Claim
30 words
A surface acoustic wave device as set forth in claim 32, wherein: said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 40
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 32, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 41
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 29, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 42
Dependent Claim
152 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused at a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; an array of output transducers disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; and a plurality of electromagnetic waveguides leading from said output transducers located on the focal line.
Claim 43
Dependent Claim
152 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused at a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; an array of output transducers disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; and a plurality of electromagnetic waveguides leading from said output transducers located on the focal line.
Claim 44
Dependent Claim
18 words
A surface acoustic wave device as set forth in claim 36, wherein: said waveguides are hybrid stripline elements.
Claim 45
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 37, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 46
Dependent Claim
17 words
A surface acoustic wave device as set forth in claim 36, wherein: said waveguides are dielectric waveguides.
Claim 47
Dependent Claim
37 words
A surface acoustic wave device as set forth in claim 39, wherein: said substrate material is practically isotropic and is of X-propagating lithium niobate produced with a Y-rotated cut at a rotation angle of approximately 121 degrees.
Claim 48
Dependent Claim
155 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
Claim 49
Dependent Claim
155 words
A surface acoustic wave (SAW) device for use as a spectrum analyzer, said device comprising: a piezoelectric substrate; an input transducer array disposed on the surface of said substrate, said array having a plurality of individual interdigital transducers connected electrically for the application of input signals, and spaced along an approximately circular arc having a transverse axis of symmetry, to provide acoustic radiation that is focused onto a focal arc of greater than zero order, laterally spaced from said axis of symmetry, each position on the focal arc being representative of a different frequency component in the input signals; and an output transducer array, disposed on said substrate in such positions as to convert acoustic signals received at the focal arc into corresponding electrical output signals representative of relatively narrow frequency bands in the input signals; wherein said input transducers have interdigital fingers that are curved to improve their ability to function as point sources.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-02-12 | 1988-08-13 | 1989-02-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-02-12 | 1992-08-13 | 1993-02-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-02-12 | 1996-08-13 | 1997-02-12 | $7700.00 | Window Closed / Lapsed |