TRANSCEIVING CIRCUIT FOR CONTACTLESS COMMUNICATION AND NFC DEVICE OR RFID READER/WRITER DEVICE COMPRISING SUCH A TRANSCEIVING CIRCUIT

• US 20110043429A1
• Filed: 03/18/2009
• Published: 02/24/2011
• Est. Priority Date: 03/20/2008
• Status: Active Grant

• Current Assignee: Quotainne Enterprises LLC
• Original Assignee: NXP B.V. (NXP Semiconductors NV)
• Inventors: Merlin, Erich
• Granted Patent: US 9,019,167 B2
• Time in Patent Office: Days
• US Class Current: 343/860
• CPC Class Codes: G06K 19/0723 the record carrier comprising an arrangement for non-contact communication, e.g. wireless communication circuits on transponder cards, non-contact smart cards or RFIDs
• CPC Class Codes: G06K 19/0726 the arrangement including a circuit for tuning the resonance frequency of an antenna on the record carrier
• CPC Class Codes: G06K 19/07749 the record carrier being capable of non-contact communication, e.g. constructional details of the antenna of a non-contact smart card

Abstract

A transceiving circuit (1, 1′) for contactless communication comprises transmitter means (3) being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to transmitting data, and an antenna (5) being connected to and driven by the transmitter means (3) with the modulated carrier signal. At least one impedance-matching capacitor (C1a) is arranged serially to the antenna (5).

Claims

1. A transceiving circuit for contactless communication comprising:

transmitter means being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to transmitting data, an antenna being connected to and driven by the transmitter means with the modulated carrier signal,

wherein at least one impedance-matching capacitor is arranged serially to the antenna.

2. The transceiving circuit as claimed in claim 1, wherein the at least one impedance-matching capacitor is arranged in a transmission path between the antenna and a tapping of a receiving path from the transmission path.

3. The transceiving circuit as claimed in claim 1, wherein the at least one impedance-matching capacitor is arranged in a transmission path between the antenna and an electromagnetic compatibility filter which is connected to output terminals of the transmitter means.

4. The transceiving circuit as claimed in claim 1, wherein the antenna comprises split antenna parts and the impedance-matching capacitor is arranged between antenna parts.

5. The transceiving circuit as claimed in claim 1, wherein there are provided two impedance-matching capacitors, which are serially arranged in transmission paths at both sides of the antenna.

6. An NFC device, an RFID reader/writer device or an RFID card, comprising a transceiving circuit according to claim 1.