Ultra-Small Step Frequency Synthesizer for Control of Phase-Locked Loop Systems

The technique of creating generators, whose frequency is controlled by the digital code, has been comprehensively developed lately. In laser systems, a specific requirement for synthesizers is the absence of phase jumps when the code that controls the value of the synthesized frequency changes. This requirement is met by a very small number of types of synthesizers due to the principle of their action. This article is devoted to solving this problem by means of a step-by-step refinement of the frequency. A method is proposed on the basis of a combination of a direct and an indirect synthesis method. The synthesizer comprises a simple unit for forming three reference frequencies, several identical units and output driver. Selection of numerical ratios intermediate frequency provides the use of cheap and reliable elemental base high degree of integration, which makes the synthesizer small-sized, highly customizable and easily replicated. Achieving high simplicity it is also based on the fact that not the task of providing the relationship between the control code and frequency formed as to provide sufficient linearity and uniqueness of this relationship and the value of the conversion factor is irrelevant since the used computer or an intelligent controller for controlling the synthesizer. This ensures the most important requirements for accuracy and the absence of jumps in the transient process.