A complete digital radio-frequency source for nuclear magnetic resonance spectroscopy

Abstract

A complete digital radio-frequency source suitable for broadband nuclear magnetic resonance applications is described. The use of a complete direct digital synthesis chip makes the design not only as a frequency- and phase-continuous tunable radio-frequency source, but also as an arbitrary wave form generator. This rf source is capable of generating a signal with frequency from dc up to 135 MHz directly. The whole design is mounted on a printed circuit board that can be inserted into one of the industry standard architecture slots in the personal computer and is controlled by the software. Details about the implementation and characteristics of the whole design are discussed in this article.