CLOCK SYNCHRONIZER TO SYNCHRONIZE A DEVICE CLOCK WITH A CLOCK OF A REMOTE DEVICE

摘要

A device (1) ) with an antenna that receives a target carrier signal (3) from a remote target (2) and transmits a device carrier signal (6) modulated with data to communicate data between the device (1) and the target (2), which device (1) comprises: clock extraction means (4) to extract a target clock (5) from the target carrier signal (3); driver means (9) to generate the device carrier signal (6) from a device clock (8); synchronization means (7) to synchronize the frequency and phase of the device clock (8) with the target clock (5), wherein that the synchronization means (7) comprise: time measurement means (10) to measure the phase difference between the target clock (5) and the device clock (8) or an internal device clock (33) related to the device clock (8) and to provide a phase information (φ1,φ2,φ3); measurement control means (20) to initiate a first time measurement that results in a first phase information (φ) and to initiate a second time measurement a fixed time period (∆T) after the first time measurement that results in a second phase information (φ2); frequency correction means (11) to correct the frequency of the device clock (8) and/or the internal device clock (33) to the frequency of the target clock (5) based on an evaluation of the first phase information (φ) and second phase information (φ2) by evaluation means (21); which measurement control means (20) are built to initiate a third time measurement after the frequency correction of the device clock (8) and/or the internal device clock (33) that results in a third phase information (φ3) evaluated by the evaluation means (21) and corrected by phase correction means (22) which correct the phase of the device clock (8) to the phase of the target clock (5).