Microwave sensor for object motion detection
US6087972A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 18, 1999 |
| Grant date | Jul 11, 2000 |
| Priority date | — |
| Expiry date | Feb 18, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S7/4021
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A microwave sensor for determining the velocity and direction of a moving object comprises a mixer, phase shifter, and receive/transmit antenna mounted in series, the mixer having a single intermediate frequency output. The intermediate frequency output is switched synchronously with the phase shifter which is switched between 0.degree. phase shift and 45.degree. phase shift. Although the mixer has only a single intermediate frequency output, the switching provides two output channel signals and with a phase difference of 90.degree. therebetween to enable determination of the direction of movement. The single intermediate frequency channel provides intrinsic gain matching of the output channels which eliminates the need for tuning in order to balance output channels as required in conventional sensor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.