An estimation method for the total radiation power (TRP) and radiation pattern of mobile antennas embedded in mobile phones using a planar near-field scanning method is proposed. The tangential magnetic fields on both front and rear faces of a mobile phone are measured both in magnitude and phase using a dual-probing technique in the time-domain. Moreover, for accurately obtaining the phase information from the measured data in the time-domain, a reliable triggering technique is introduced. The far-field is calculated by using the near-field to far-field transformation based on the equivalent principle and the image method. The calculated TRP and radiation pattern are validated by comparison with the measured TRP and radiation pattern in an authorized anechoic chamber, and good agreement has been achieved.