Dispersive electromagnetic surface acoustic wave transducer
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorThomas J. Moran
Life of this patent
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Abstract
A surface acoustic wave electromagnetic transducer (SAW EMT) having a meander line with progressively smaller spacing between conductors produces a surface, acoustic, traveling, exploratory, output signal that is greatly dispersed, when excited with a pulse electrical signal; and a corresponding compressed electrical output signal is produced from a received acoustic signal. The transducer may be used either to transmit or receive signals.
Claims7
A dispersive surface acoustic wave electromagnetic transducer comprising:
- a. means for providing a magnetic field;
- and
- b. a meander line coil having conductors with progressively changing spacing between conductors at a predetermined rate of change of spacing, positioned in the said magnetic field.
A nondestructive surface examining system comprising:
- a. a first dispersive surface acoustic wave electromagnetic transducer having a permanent magnet field and a meander line coil with a predetermined rate of change of conductor spacing positioned in the said field;
- the said transducer positioned on the said surface for generating a surface acoustic wave;
- b. a second dispersive surface acoustic wave electromagnetic transducer substantially identical with the said first transducer positioned on the said surface for detecting a surface acoustic wave;
- c. means including an electronic pulser for driving the said first transducer;
- and
- d. means including a receiver and an oscilloscope cooperating with the said second transducer for displaying the said received surface acoustic wave.
An electromagnetic dual transducer dispersive surface acoustic wave device for generating a surface acoustic wave in a metallic surface and detecting a resulting reflected surface acoustic wave, the said dual transducer comprising:
- a. a permanent magnet structure providing a magnetic field;
- b. a meander line with conductor spacing progressively changing in spacing at a determined and equal rate in both directions from the center of the said meander line;
- and
- c. means for positioning the said meander line in the said field.
Dependencies are inferred from the claim text.