Patent ID: 9019167
Filing Date: 2015-04-28
Classification: G06K

Abstract:
1. A transceiving circuit for contactless communication comprising: transmitter means configured to generate an electromagnetic carrier signal and to modulate the carrier signal for transmitting data; an antenna, wherein the antenna is connected to the transmitter means and driven by the transmitter means using the modulated carrier signal; a first impedance-matching capacitor formed in a first transmission path that is coupled to a first output terminal of the transmitter means; a second impedance-matching capacitor formed in a second transmission path that is coupled to a second output terminal of the transmitter means; a tapping point of a receiving path that is coupled to the first transmission path so that the tapping point is interposed between the first output terminal and the first impedance-matching capacitor; a phase adjusting capacitor that is switched into the receiving path; and an electromagnetic compatibility filter that is connected between the first and second output terminals of the transmitter means and the first and second impedance-matching capacitors, wherein the first impedance-matching capacitor is interposed between the tapping point and the antenna, wherein the antenna comprises first and second capacitors and an inductor, wherein the first and second capacitors are connected together in series and the inductor is coupled between the first and second impedance matching capacitors in parallel with the first and second capacitors.