Directional ultrasonic transducers
US4408493A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 24, 1982 |
| Grant date | Oct 11, 1983 |
| Priority date | — |
| Expiry date | Mar 24, 2002 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/0422
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus for generating acoustic waves of wavelength .lambda. in an electrically conductive object includes an electromagnetic acoustic transducer, with a source of magnetic flux for producing a magnetic field in the object, a first periodic coil within the field, and a second periodic coil within the field and offset from the first coil by .lambda./4. A first port of a four port hybrid is connected to the first coil and a second port is connected to the second coil, with a 90.degree. phase delay element interposed between the first port and the first coil. A signal generator provides an input signal at a frequency corresponding to .lambda., with a transmitter for applying the signal to either a third or a fourth port of the hybrid to generate a unidirectional wave in one of two opposite directions. An apparatus for detecting acoustic waves includes a first receiver connected to the third port and a second receiver connected to the fourth port.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.