A Precision Digital Phase Generator

The design of a digital phase generator which produces two outputs of frequency f, between which the phase shift can be varied from 0 to 360° in steps of 1°, from an input frequency of 360f, is described. The system design is described in detail. The circuit design and the choice of the circuit elements are discussed. Fast logic elements have been used in the construction of the instrument. A brief analysis of the performance of the system is also given. From the experimental results, which agree with the calculated performance, it is found that the accuracy of the system varies and is as high as 0.05 percent when the phase shift is 359°. The accuracy of the system is limited only by the propagation delays of the logic elements used and therefore can be improved by using faster logic elements.