Transponder and corresponding operating method
In accordance with a first aspect of the present disclosure, a radio frequency identification (RFID) transponder is provided, comprising a modulator and a controller, wherein: the modulator is configured to generate a modulated signal to be transmitted to an external RFID reader; the controller is configured to increase a transmitter impedance during a first period of time; the controller is configured to decrease the transmitter impedance by enabling the modulator during a second period of time. In accordance with a second aspect of the present disclosure, a corresponding method of operating a radio frequency identification (RFID) transponder is conceived.
1. A radio frequency identification, RFID, transponder, comprising a modulator and a controller, wherein:
the modulator is configured to generate a modulated signal to be transmitted to an external RFID reader;
the controller is configured to increase a transmitter impedance during a first period of time;
the controller is configured to decrease the transmitter impedance by enabling the modulator during a second period of time; and
the controller is configured to increase the transmitter impedance by disabling a low-dropout (LDO), regulator of the RFID transponder.
2. The RFID transponder of claim 1 , wherein the controller is configured to increase the transmitter impedance by disabling a low-impedance path within the RFID transponder.
3. The RFID transponder of claim 1 , wherein disabling the LDO regulator of the RFID transponder results in a higher load amplitude for a load of the RFID transponder compared to when the LDO is enabled.
4. The RFID transponder of claim 1 , wherein the LDO regulator is disabled by opening a first switch.
5. The RFID transponder of claim 1 , wherein the modulator is enabled by closing a third switch.
6. The RFID transponder of claim 1 , wherein the controller is configured to repeatedly increase the transmitter impedance.
7. The RFID transponder of claim 1 , wherein the controller is configured to disable the modulator after the second period of time.
8. The RFID transponder of claim 1 , being an RFID tag.
9. A radio frequency identification, RFID, transponder, comprising a modulator and a controller, wherein:
the modulator is configured to generate a modulated signal to be transmitted to an external RFID reader;
the controller is configured to increase a transmitter impedance during a first period of time;
the controller is configured to decrease the transmitter impedance by enabling the modulator during a second period of time; and
the controller is configured to increase the transmitter impedance by disabling a voltage limiter of the RFID transponder.
10. The RFID transponder of claim 9 , wherein the voltage limiter is disabled by opening a second switch.
11. A method of operating a radio frequency identification, RFID, transponder, the RFID transponder comprising a modulator and a controller, the method comprising:
the modulator generates a modulated signal to be transmitted to an external RFID reader;
the controller increases a transmitter impedance during a first period of time;
the controller decreases the transmitter impedance by enabling the modulator during a second period of time; and
the controller increases the transmitter impedance by disabling one of either a low-dropout, (LDO) regulator or a voltage limiter of the RFID transponder.
12. The method of claim 11 , wherein the controller repeatedly increases the transmitter impedance.
13. The method of claim 11 , wherein the controller increases the transmitter impedance by disabling a low-impedance path within the RFID transponder.
14. The method of claim 11 , wherein disabling one of either the LDO regulator or the voltage limiter of the RFID transponder results in a higher load amplitude for a load of the RFID transponder compared when either the LDO or voltage limiter are enabled.
15. The method of claim 14 , wherein the LDO regulator is disabled by opening a first switch.
16. The method of claim 11 , wherein the RFID transponder is a near field communication (NFC) transponder.
17. The method of claim 11 , wherein the voltage limiter is disabled by opening a second switch.
18. The method of claim 11 , wherein the modulator is enabled by closing a third switch.
19. The method of claim 11 , wherein the controller disables the modulator after the second period of time.
20. The method of claim 11 , wherein the RFID transponder is an RFID tag.