Patent ID: 6533178
Filing Date: 2003-03-18
Classification: G06K

Abstract:
A device for a contactless transmission of data, comprising:a data transceiver and a portable data carrier; said data transceiver including: a transmitting device for producing a first signal of a given frequency; a receiving device for receiving a second signal of a given frequency; a line of unknown length, said line having a characteristic impedance; a data transceiver antenna connected to said transmitting device and to said receiving device via said line of unknown length; a matching circuit configuration connected between said data transceiver antenna and at least one of said transmitting device and said receiving device, said matching circuit configuration having at least one resistance limiting a factor Q for matching a total impedance to the characteristic impedance of said line, and said matching circuit having an additional loss resistance; said portable data carrier including: a data carrier antenna for transmitting and for receiving an induced signal; and a circuit configuration, connected to said data carrier antenna, for processing the induced signal and for producing a signal to be transmitted to said data transceiver antenna.