| 摘要 |
In one embodiment a method for a phase calibration in a frontend circuit of a near field communication, NFC, tag device has the steps receiving a reference signal (Sr) generated by an NFC signal generator device, receiving a phase calibration command, generating an active load modulation signal (Sf) with a preconfigured value of a phase difference (P1) with respect to the reference signal (Sr) of the NFC signal generator device, measuring an amplitude (Vm1) of a test signal (St) present at an antenna of the NFC tag device, said test signal (St) resulting from overlaying of the reference signal (Sr) with the active load modulation signal (Sf), repeating the steps: modifying the value of the phase difference, providing the active load modulation signal (Sf) with the modified value of the phase difference (P2), measuring an amplitude (Vm2) of the test signal (St) and comparing the measured amplitude (Vm2) with the previously measured amplitude (Vm1) or with a reference amplitude (Vref) until the measured amplitude fulfils a predefined condition, storing the value of the phase difference (Px) of the previously measured amplitude (Vm1). |
