Transponder for radiocommunication system, particularly for measuring the distance between two stations
US4183022A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 2, 1977 |
| Grant date | Jan 8, 1980 |
| Priority date | — |
| Expiry date | Jun 2, 1997 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/84
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system for measuring the distance between an interrogating station and a transponder station comprises, at the latter station, a receiver for a phase-modulated UHF wave emitted by the interrogating station and a transmitter for sending back an outgoing main carrier modulated in phase by a locally generated subcarrier. A first oscillator generates a wave whose frequency is a subharmonic of the frequencies of both the incoming and the outgoing main carrier and from which there are derived, besides this outgoing carrier, a heterodyning oscillation and a reference oscillation which are both amplitude-modulated by the output of a second oscillator whose frequency matches that of the incoming subcarrier and which also serves as a source of the locally generated outgoing subcarrier. The amplitude-modulated heterodyning oscillation is mixed with the incoming carrier wave to produce an i-f oscillation with a central frequency matching that of the reference oscillation and with two pairs of sidebands respectively due to the phase modulation of the incoming carrier and to the amplitude modulation of the heterodyning oscillation. The first oscillator is provided with a phase-locking loop inc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.