Statistical properties of the phase as well as the quadrature components of the ionospheric scintillating radio signal are investigated using data received from the ATS 6 radio beacon experiment. For weak scintillation the phase-quadrature components dominate the fluctuations. When the scintillation level is increased, the multiple scattering seems to have the effect of equalizing th power between the two quadrature components. The phase spectra are consistent with power law irregularity models. For strong scintillations the phase spectra become flattened. The spectra for the quadrature components as well as the frequency dependence of the mean square phase fluctuations are studied. The experimental data were interpreted using existing scintillation theories.