Receiver imperfections and CYCLOPS: an alternative description

We present a quantitative approach to describe the spectral artifacts that are introduced into the NMR spectrum by imperfections of the receiver electronics of the NMR spectrometer ("mirror image" or "ghost", "transmitter spike"). In contrast to the commonly used graphical representation, it is based on a rigorous algebraic treatment and provides quantitative results on the intensities and phases of the artifacts easily. We apply this approach to the quantitative explanation of the well-known Cyclically Ordered Phase Sequence phase cycle (CYCLOPS) that serves to suppress the receiver imperfections and thus to remove the artifacts from the frequency spectrum. Finally, we compare the algebraic results with a graphical approach and demonstrate that the application of CYCLOPS minimizes the artifacts even if the spectrometer has deficiencies in the transmitter electronics.