A novel technique for programmed generation of multifrequency composite sinusoids

Test signals consisting of a set of composite sinusoids have found increasing application recently in the non-linear control system testing field. This paper presents a new approach to the implementation of a multifrequency signal generator capitalizing on recent advances in digital techniques. The instrument generates N sinusoids of programmable relative frequency over a very wide dynamic range, in excess of 10¿4to 104Hz. Relative phase shift and amplitude ratio are also programmable. The new technique makes possible relative frequency jitter of zero as well as identical and low noise content for all N sinusoids. Extensive simulation studies have fully established zero relative phase error, and zero relative harmonic ratio error; both being prime conditions for accurate multifrequency test signals.