Method and apparatus for measuring a phase-modulated signal

Abstract

Abstract The invention relates to a method for measuring the phase of a phase-modulated signal (5). The signal (5) is measured at at least five different test points (P1-P5). From the associated measurement values (E1-E5), at least three sets of measurement values are formed in such a manner that a phase value phi i arctran (Zi/Ni) where i = 1,2,...,m>3 can be calculated from each of the three sets of measurement values. For the signal having the frequency of the carrier wave, the same correct phase value phi is calculated from all three sets of measurement values. The essential factor for the method according to the invention is the finding that a correct phase value phi = arctran <IMAGE> can also be calculated from linear combinations of the Zi and the Ni. The factors ai are then selected in such a manner that the phase error has at least three zeros as a function of the phase stages between the test points (P1-P5). This significantly reduces the systematic errors in the phase measurement. The method according to the invention is particularly suitable for evaluating stripe images, particularly of multi-stripe images. <IMAGE>

Inventors

• 👤 Michael Dr. Küchel

Bibliographic Details