Radio frequency receiver for a NMR instrument
US4992736A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 4, 1989 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Aug 4, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R33/3607
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A receiver processes an NMR signal to produce a baseband image information signal from which two quadrature component signals are derived. An intermediate frequency section mixes the received NMR signal with two reference signals to shift the image information into a frequency band having a bandwidth BW and centered at a frequency that is 1.5 times the bandwidth BW. The resultant signal is filtered to remove extraneous signals outside the image information band. An analog to digital converter samples the filtered signal at a rate that is twice the bandwidth BW and digitizes the samples into a digital signal. A quadrature detector derives I and Q output signals from the digital signal by alternately selecting digital samples and negating every other sample selected for each of the I and Q output signals. The quadature detector also digitally filters the I and Q signals which are then used to construct an NMR image.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.