发明名称 |
Analogue-to-digital converter and analogue-to-digital conversion system embodying said converter |
摘要 |
An N-bit analogue-to-digital converter can increase the resolution by 3 bits, by very precise coding of the differential phase at the output of the electro-optic phase modulator controlled by the electric signal to be converted. The optical signals obtained are processed by an electro-optic device that outputs electric signals that are functions of the sine and cosine of the phase. A coding device uses the symmetry of the trigonometric circle partitioned into four consecutive sectors between 0 and 27 pi in order to convert the absolute values of the electric signals obtained on (N-3) bits, independently of the home sector of the phase. A transcoding device uses the value of the sine and cosine coded on (N-3) bits, to output a value V of the electric signal, on N bits, as a function of the home sector. The conversion system according to the invention comprises a first N-bit analogue-to-digital converter doing a very precise but ambiguous conversion of the electric signal, and a second analogue-to-digital converter to eliminate the ambiguity.
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申请公布号 |
US5629699(A) |
申请公布日期 |
1997.05.13 |
申请号 |
US19950499957 |
申请日期 |
1995.07.10 |
申请人 |
THOMSON-CSF |
发明人 |
CHAZELAS, JEAN;LE PARQUIER, GUY;RENAULT, FRANÇOIS |
分类号 |
G01J9/02;G02F7/00;H03M1/12;H03M1/64;H03M7/00;(IPC1-7):H03M1/00 |
主分类号 |
G01J9/02 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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