An RF (radio frequency) positioning system and related method for automated or assisted eye-docking in ophthalmic surgery. The system includes an RF detector system on a laser head and an RFID tag on a patient interface to be mounted on the patient's eye. The detector system includes four RF antennas located on a horizontal plane for detecting RF signals from the RFID tag, where one pair of antennas are located along the X direction at equal distances from the optical axis of the laser head and another pair are located along the Y direction at equal distances from the optical axis. Based on relative strengths and phase difference of the RF signals detected by each pair of antennas, the RF detector system determines whether the patient interface is centered on the optical axis. The RF detector system controls the laser head to move toward the patient interface until the latter is centered on the optical axis.