Coherent detection architecture for remote calibration of coherent systems
US5809087A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 25, 1996 |
| Grant date | Sep 15, 1998 |
| Priority date | — |
| Expiry date | Oct 25, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01S13/90
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An architecture for remote calibration of coherent systems uses coherent reference and calibration signals that contain the relative amplitude and phase information desired in the calibration process. Circuitry extracts the relevant amplitude and phase information needed for the calibration while compensating for non-synchronized clocks and the effects of Doppler shifts due to relative motion of the transmitting and receiver platforms. The coherent detection architectures can be used effectively with any scheme designed to determine the relative amplitudes and phases of the signals emitted from the different elements of the phased array. These architectures are particularly applicable to coherent encoding calibration procedures that enhance the effective SNR by using coherent transmission of orthogonal transform encoded signals from N elements of the phased array. In an example calibration architecture, coherent elemental signals are encoded using controlled switching of the delay phase control circuits themselves to effectively generate a perfect orthogonal transform encoding of the signal vectors, even though the control circuits may be imperfect; no additional encoding hardware …
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