Extraction of quadrature phase information from multiple pulse NMR signals

Abstract

A multiple pulse sequence (8-pulse sequence) used for high-resolution solid state NMR is analyzed with regard to the information available from each of the four wide sampling windows. It is demonstrated that full quadrature phase information can be obtained using only a single phase detector and that, for the commonly encountered situation where the spectral width is much less than the folding frequency, the signals from the various windows can be combined easily using standard complex Fourier transform software. An improvement in the signal-to-noise ratio of √3 is obtained over either standard single of quadrature phase detection schemes. Procedures for correcting spectral distortions are presented.