Potential use of the undersampling technique in the acquisition of nuclear magnetic resonance signals

This communication reviews the use of undersampling techniques to acquire NMR signals. Undersampling transforms bandpass free induction decay (FID) signals, centered at high frequencies, into lowpass signals or bandpass signals centered at much lower frequencies. Consequently, the analog electronic stages that perform the demodulation can be eliminated, gaining in stability and reducing the phase distortion while maintaining an equivalent or better signal to noise ratio when an adequate sampling rate is chosen. The technique has been tested on a BRUKER BIOSPEC BMT 47/40, and the results show that undersampling could be used to process NMR and MRI signals, extending the range of applications of the 'digital radio' techniques to NMR and MRI apparatus.