Transponder and method for operating a transponder

1 . A transponder, comprising:

a receiving device for receiving a first signal at a first carrier frequency originating from an external transmitter; and

a transmitting device for transmitting a second signal at a second carrier frequency to an external receiver,

wherein the second carrier frequency is higher than the first carrier frequency, and

wherein the second carrier frequency is n+0.5 times the first carrier frequency, and n is a natural number greater than 1.

2 . The transponder according to claim 1 , wherein the transponder further comprises a filter for filtering out a first carrier signal at the first carrier frequency from the first signal and/or a device for generating the second carrier signal with the second carrier frequency for the second signal.

3 . The transponder according to claim 2 , wherein the device for generating the second carrier signal generates the second carrier signal from the first signal or from the first carrier signal.

4 . The transponder according to claim 2 , wherein a PLL circuit generates the second carrier signal on the basis of the first carrier signal.

5 . The transponder according to claim 1 , wherein the transponder has a passive energy source.

6 . The transponder according to claim 1 , wherein the transmitting device transmits the second signal while the receiving device is receiving the first signal.

7 . A method for operating a transponder, the method comprising:

receiving, via a transponder, an input signal having a first carrier frequency;

providing a transmit carrier signal having a second carrier frequency that is n+0.5 times the first carrier frequency, where n is a natural number greater than 1;

providing a transmit signal having the second carrier frequency; and

transmitting the transmit signal by the transponder.

8 . The method according to claim 7 , further comprising:

extracting an input carrier signal having the first carrier frequency from the input signal; and

producing the transmit carrier signal having the second carrier frequency based on the receive carrier signal.

9 . The method according to claim 7 , wherein the transponder transmits the transmit signal while it is receiving the receive signal.

10 . The method according to claim 7 , wherein the transmission of the transmit signal takes place with a second carrier frequency of 6.78 MHz, 8.1 MHz, or 13.56 MHz.