| 摘要 |
2120746 9307679 PCTABS00021 An NMR receiver (60) utilizing the Sigma-Delta modulation method implemented in the analog-to-digital converter (88) device to enable the use of much simpler analog anti-aliasing filters (86) that have a wider bandwidth. The analog filters do not induce phase distorsion of the signal in the operating frequency and thus eliminates the need for first order phase correction by the digital signal processor. Further, there is no requirement for adjustment in the filters (86) since the digital decimation filter (88) contained within the analog-to-digital converter device (88) acts as a digital lowpass filter.
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