Electromagnetic wave, reflective type, low cost, active proximity sensor for harsh environments
US5905380A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 26, 1996 |
| Grant date | May 18, 1999 |
| Priority date | — |
| Expiry date | Apr 26, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V8/005
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An electromagnetic, reflective type, active proximity sensor includes a transmitter, the transmitter including a voltage controlled oscillator circuit, a transmitter circular waveguide and a transmitter polarization circuit. The voltage controlled oscillator circuit generates an output signal which is modulated such that the frequency of the output signal varies over time between a range of frequencies. The frequency varying, output signal is provided to the transmitter circular waveguide and propagated to the transmitter polarization circuit where it is circularly polarized in a first circular direction. The circularly polarized, frequency varying, output signal is radiated by the transmitter to the target, where it strikes the target and reflects back toward the sensor to form return signals. The return signals, upon being reflected, rotate in a second circular direction opposite to the first circular direction. The return signals also respectively exhibit one of the frequencies corresponding to the range of frequencies associated with the circularly polarized, frequency varying, output signal. The active proximity sensor also includes a receiver, the receiver including a receive…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.