Phase modulation (PM) method has been introduced to study periodic variability within variable stars by converting phase shifts into time delays of the traveled light path known as the light time travel effect (LTTE). This method was highly successful in detecting binary companions and in studying Blazhko-type modulation in RR Lyrae and δ Scuti stars. However, both binary motion and intrinsic Blazhko modulation introduce periodic phase variations, which can produce very similar signatures in the PM time-delay curves, particularly when the period ranges of the two effects overlap or when both effects may be present simultaneously. As a result, some stars might be misclassified as Blazhko or Binary type stars. One way to discriminate between the tow effects is to adopt the O-C diagram to test for binarity, although recent studies show the complexity of this approach in the presence of other intrinsic variations. Another approach is to examine the multiplets seen in the Fourier transform . In this work, we investigate an other method to distinguish between intrinsic Blazhko and binary orbital modulations using Wavelet analysis for characterizing the behavior of the modulation over a wide range of time scale, the time series are decomposed into time–frequency space to determine both the dominant modes of variability and how those modes vary in time. By carefully investigating some RR Lyrae stars where the two effects have been confused or simultaneously present, the wavelet analysis turned out to be a powerful tool to separate the two effects and to investigate other types of intrinsic variations present in RR Lyrae stars like period breaks and secular period changes .