摘要:
A data transmission system for the non-contact transmission of data between a station (1) and a portable data carrier (2). The station (1) includes a station transmitter (3) operating at a predetermined frequency for generating a first signal and a demodulator (35) for detecting a second signal superimposed on the first signal. An antenna (5) is coupled via a length of cable (4) to the station transmitter (3) via a matching circuit (6) so as to be operative at said frequency regardless of the length of the cable (4). The portable data carrier (2) includes supply means (13) for coupling to a source of electric power and a data carrier tuned antenna circuit (10, 55) inductively coupled with the station transmitter (3) so as to receive power from the station (1). A data carrier data modulator (14) is provided for modulating the first signal with the second signal in response to data stored within the data carrier (2) and, by means of said inductive coupling, enabling the data to be transmitted from the data carrier (2) to the station (1).
摘要:
A data transmission system for the non-contact transmission of data between a station (1) and a portable data carrier (2). The station (1) includes a station transmitter (3) operating at a predetermined frequency for generating a first signal and a demodulator (35) for detecting a second signal superimposed on the first signal. An antenna (5) is coupled via a length of cable (4) to the station transmitter (3) via a matching circuit (6) so as to be operative at said frequency regardless of the length of the cable (4). The portable data carrier (2) includes supply means (13) for coupling to a source of electric power and a data carrier tuned antenna circuit (10, 55) inductively coupled with the station transmitter (3) so as to receive power from the station (1). A data carrier data modulator (14) is provided for modulating the first signal with the second signal in response to data stored within the data carrier (2) and, by means of said inductive coupling, enabling the data to be transmitted from the data carrier (2) to the station (1).