Direct frequency synthesizer using powers of two synthesis techniques

Abstract

A fast switching broadband signal synthesizer method and structure are provided which not only has the ability to change frequency and amplitude quickly, but with a minimal dwell time required before switching can again take place. A signal translator can also be constructed in accordance with this invention in order to convert the output frequency of a companion signal source to any desired frequency while retaining the fast switching speed and switching rate of the signal synthesizer. Amplitude, phase, and frequency modulation of the companion signal are preserved during the translation process. A direct frequency synthesizer is provided wherein internal signals which are combined to generate any output frequency are derived from a single fixed frequency oscillator. By utilizing a single reference frequency oscillator in accordance with this invention, the amount of circuitry required to construct a direct frequency synthesizer is greatly reduced. Because all internal signals are derived from one reference frequency oscillator, the close-in-phase noise of the internal signals are correlated, thus providing an output signal having low phase noise. All internal frequency increments and number of frequency selector switch positions have numerical values that are an exact-power-of-two.