System for determining size and location of defects in material by use of microwave radiation
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorJohn M. Liu
Life of this patent
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Abstract
Microwave radiation emitted from a single antenna is focused on a targeted material from which reflected radiation is received by the same antenna to provide signal measurement data from which detected material defects are evaluated by determination of void location and size. Antenna position and orientation is adjusted to obtain the signal measurement data from of the microwave radiation reflection along at least two target incidence paths from the same target location, one of which is normal to said targeted surface of the material and the other oblique thereto at a scattering angle at which the signal radiation intensity is minimized.
Claims8
A system for evaluating defects detected within non-metallic material by emission of microwave radiation from a single antenna along a normal incidence path and measurement of microwave radiation reflection, the improvement residing in:
- adjusting position and orientation of the antenna for also emitting the microwave radiation along at least one oblique incidence path at a selected scattering angle to said normal incidence path at which intensity of the microwave radiation reflection is minimized;
- and determining location and size of the detected defects from said measurements of the intensities of the microwave radiation reflection along both the normal and oblique incidence paths.
A system for evaluating defects detected within non-metallic material by emission of microwave radiation from a single antenna along a normal incidence path perpendicular to a targeted surface of said material and measurement of emitted microwave radiation reflection, the improvement residing in:
- adjusting position and orientation of the antenna for focusing the microwave radiation along at least one oblique incidence path at a selected scattering angle to said normal incidence path at which measured intensity of the microwave radiation reflection is minimized;
- and determining location of the detected defect in the material from said measurements of the intensities of the reflections along both the normal and oblique incidence paths.
A system for evaluating defects detected within non-metallic material by exposure to microwave radiation from a single antenna focused along a normal incidence path perpendicular to a targeted surface of said material and measurement of microwave radiation reflections from the material, the improvement residing in:
- adjusting position and orientation of the antenna for refocusing the microwave radiation along at least one oblique incidence path at a selected scattering angle to said normal incidence path at which intensity of the microwave radiation reflection is minimized;
- and determining size of the detected defects from thickness and lateral extent of voids as functions of the intensities of the microwave radiation reflections.
Dependencies are inferred from the claim text.