| Patents for G01S 13 - Systems using the reflection or reradiation of radio waves, e.g. radar systems; Analogous systems using reflection or reradiation of waves whose nature or wavelength is irrelevant or unspecified (37,701) | |
|---|---|
| 01/1976 | |
| 01/06/1976 | US3931420 Temperature compensated acoustic surface wave device |