Low drift relative phase sensor employing surface acoustic waves
First Claim
1. A sensor for sensing the delay difference between first and second signals having substantially identical wave forms comprising a piezoelectric body having a surface,a row of n first and second input transducer pairs disposed on said surface in a first direction,said pairs of input transducers being offset from one another by offset distances each bearing a relationship of λ
- /16means for coupling said first and second signals to said first and second input transducers, respectively, so that parallel acoustic waves of a wavelength λ
are produced on the active region of said surface,said surface acoustic waves traveling in a second direction normal to the row of said first and second transducer pairs,a row of output transducers disposed on said surface substantially parallel to said first and second transducer pairs so that the amplitude of the signal produced at each output transducer by interference between input signals from said first and second transducers of the corresponding pair represents a discrete delay difference between said first and second signals coupled to said input transducers.
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Accused Products
Abstract
Pairs of input transducers are formed on the surface of a piezoelectric crystalline body. The input transducers in each pair produce adjacent parallel surface acoustic waves of opposite polarity and specific phase difference which are sensed by a corresponding output transducer. The input transducers of each pair are offset from one another by amounts related to the wavelength of the surface acoustic wave so that a maximum cancellation of the voltages induced in the output transducers by the acoustic waves can be used to indicate the relative delay or phase difference of signals applied to the input terminals and to do so in a manner which is insensitive to temperature variation from one point to another in the piezoelectric crystal.
16 Citations
4 Claims
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1. A sensor for sensing the delay difference between first and second signals having substantially identical wave forms comprising a piezoelectric body having a surface,
a row of n first and second input transducer pairs disposed on said surface in a first direction, said pairs of input transducers being offset from one another by offset distances each bearing a relationship of λ - /16
means for coupling said first and second signals to said first and second input transducers, respectively, so that parallel acoustic waves of a wavelength λ
are produced on the active region of said surface,said surface acoustic waves traveling in a second direction normal to the row of said first and second transducer pairs, a row of output transducers disposed on said surface substantially parallel to said first and second transducer pairs so that the amplitude of the signal produced at each output transducer by interference between input signals from said first and second transducers of the corresponding pair represents a discrete delay difference between said first and second signals coupled to said input transducers. - View Dependent Claims (2, 3, 4)
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Specification
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- Resources
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Current AssigneeLockheed Martin Corporation (Martin Marietta Corporation)
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Original AssigneeLockheed Martin Space Operations Company (Martin Marietta Corporation)
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InventorsWard, Robert B.
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Primary Examiner(s)Nussbaum, Marvin L.
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Application NumberUS06/453,277Time in Patent Office575 DaysField of Search333/150-155, 333/193-196, 331/107 A, 310/313 R, 310/313 A, 310/313 B, 310/313 C, 310/313 D, 324/82, 324/80, 364/821US Class Current333/154CPC Class CodesG01R 25/00 Arrangements for measuring ...H03H 9/1455 constituted of N parallel o...H03H 9/76 Networks using surface acou...
