Abstract: An NFC device for contactless communication comprises transmitter means being adapted to generate an electromagnetic carrier signal and to modulate the carrier signal according to transmitting data, and an antenna having an inductor, which antenna is connected to and driven by the transmitter means with the modulated carrier signal. AC coupling capacitors are coupled to the inductor of the antenna, wherein the AC coupling capacitors are further connected to inputs of switches. The outputs of these switches can be switched between ground potential and inputs of rectifier means. The outputs of the rectifying means are fed to power supply rails of the NFC device.

Abstract: Active load modulation antennas for contactless systems typically require the presence of a battery power source in the transponder device. The transponder typically cannot be powered by the reader device alone and also transmit an active load modulation signal. Embodiments in accordance with the invention are disclosed that allow transponder devices to transmit an active load modulation signal when powered only by the reader in the contactless system.

Abstract: In a near field communication partner device (1) intended for the contactless transmission of digital data to be transmitted having a transmission circuit (2), the transmission circuit (2) comprises a modulation circuit (17) for the amplitude modulation of a carrier signal (CS), which modulation circuit (17) comprises a circuit stage (20, 20?) for producing a plurality of different resistance values (RW1, RW1?) that act on a signal output (TX1, TX2), which resistance values (RW1, RW1?) can be transformed, by means of a signal processing circuit (3) arranged to transform resistance values that belongs to the communication partner device (1), into transformed resistance values (RW2, RW2?), which transformed resistance values (RW2, RW2?) are responsible for damping a transmission coil (7) of the communication partner device (1) when modulated low-level carrier signal sections are generated in a modulated carrier signal.

Abstract: A transceiving circuit (1, 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) having an inductor (Lant), which antenna (5) is connected to and driven by the transmitter means (3) with the modulated carrier signal. AC coupling capacitors (C4) are coupled to the inductor (Lant) of the antenna (5), wherein the AC coupling capacitors (C4) are further connected to inputs of switches (S1, S2). The outputs of these switches (C4) can be switched between ground potential and inputs of rectifier means (6). The outputs of the rectifying means (6) are fed to power supply rails (PbF1, PbF2) of the transceiving circuit (1).

Abstract: In a communication partner device (1) intended for the contactless transmission of digital data to be transmitted having a transmission circuit (2), the transmission circuit (2) comprises a modulation circuit (17) for the amplitude modulation of a carrier signal (CS), which modulation circuit (17) comprises a circuit stage (20, 20?) for producing a plurality of different resistance values (RW 1, RW 1?) that act on a signal output (TX1, TX2), which resistance values (RW1, RW1?) can be transformed, by means of a signal processing circuit (3) arranged to transform resistance values that belongs to the communication partner device (1), into transformed resistance values (RW2, RW2?), which transformed resistance values (RW2, RW2?) are responsible for damping a transmission coil (7) of the communication partner device (1) when modulated low-level carrier signal sections are generated in a modulated carrier signal.

Abstract: A radio frequency (RF) communication device (1, 1?, 10) has data transmission means and data receiving means. The data transmission means comprise load modulating means (3) being adapted to receive a radio frequency carrier signal (CS1, CS2) emitted by another RF communication device (1, 1?, 10) and to modulate the RF carrier signal (CS1, CS2) by means of load modulation in accordance with data to be sent. The data receiving means comprise a RF frequency carrier signal generator (4) being adapted to emit a radio frequency carrier signal (CS1, CS2) and load demodulating means (5) being connected to an emission path (4a) of the radio frequency carrier signal and demodulating the radio frequency carrier signal (CS1, CS2) when it has been load modulated by another RF communication device (1, 1?, 10).

Abstract: An electric circuit for a communication device (200) for communicating with a further communication device (500), the electric circuit comprising an inductive antenna element (101) adapted for inductively communicating with the further communication device (500), a capacitive antenna element (102) adapted for capacitively communicating with the further communication device (500), and a common matching circuit (105) adapted to match impedances of the inductive antenna element (101) and of the capacitive antenna element (102).

Abstract: A radio frequency (RF) communication device (1, 1?, 10) has data transmission means and data receiving means. The data transmission means comprise load modulating means (3) being adapted to receive a radio frequency carrier signal (CS1, CS2) emitted by another RF communication device (1, 1?, 10) and to modulate the RF carrier signal (CS1, CS2) by means of load modulation in accordance with data to be sent. The data receiving means comprise a RF frequency carrier signal generator (4) being adapted to emit a radio frequency carrier signal (CS1, CS2) and load demodulating means (5) being connected to an emission path (4a) of the radio frequency carrier signal and demodulating the radio frequency carrier signal (CS1, CS2) when it has been load modulated by another RF communication device (1, 1?, 10).

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).

Abstract: In a communication partner device (1) intended for the contactless transmission of digital data to be transmitted having a transmission circuit (2), the transmission circuit (2) comprises a modulation circuit (17) for the amplitude modulation of a carrier signal (CS), which modulation circuit (17) comprises a circuit stage (20, 20?) for producing a plurality of different resistance values (RW 1, RW 1?) that act on a signal output (TX1, TX2), which resistance values (RW1, RW1?) can be transformed, by means of a signal processing circuit (3) arranged to transform resistance values that belongs to the communication partner device (1), into transformed resistance values (RW2, RW2?), which transformed resistance values (RW2, RW2?) are responsible for damping a transmission coil (7) of the communication partner device (1) when modulated low-level carrier signal sections are generated in a modulated carrier signal.

Abstract: A transceiving circuit (1) for contactless communication comprises transmitter means (3) to generate an electromagnetic carrier signal, to modulate the carrier signal according to transmitting data and to drive an antenna (5) with the modulated carrier signal, and receiver means (4) to sense response signals being received at the antenna (5) and to demodulate the response signals. The transmitter means (3) are connected to the antenna (5) by at least a first transmitting path (TX1), wherein a first DC decoupling capacitor (C1b) is switched into the first transmitting path (TX1). A receiving path (RX) branches off from the first transmitting path (TX1) to the receiver means (4). A second DC decoupling capacitor (C1c) is switched into the first transmitting path (TX1) in series to the first DC decoupling capacitor (C1b). The receiving path (RX) branches off from the first transmitting path (TX1) at a branching point (C) between the first and second DC decoupling capacitors (C1b, C1c).

Abstract: A transceiving circuit (1, 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) having an inductor (Lant), which antenna (5) is connected to and driven by the transmitter means (3) with the modulated carrier signal. AC coupling capacitors (C4) are coupled to the inductor (Lant) of the antenna (5), wherein the AC coupling capacitors (C4) are further connected to inputs of switches (S1, S2). The outputs of these switches (C4) can be switched between ground potential and inputs of rectifier means (6). The outputs of the rectifying means (6) are fed to power supply rails (PbF1, PbF2) of the transceiving circuit (1).

Abstract: In a signal processing circuit (3) for a contactlessly communicating communication partner device (1), there are provided a transmitted-signal path (9) and a received-signal path (10), the received-signal path (10) branching off from a branch point (AP) present on the transmitted-signal path (9), a filter stage (11) and a matching stage (12) connected downstream of the filter stage (11) being provided on the transmitted-signal path (9), the filter stage (11) having a resonant frequency that is in a frequency range the center frequency value of which matches an upper sideband frequency, and the branch point (AP) being situated between the filter stage (11) and the matching stage (12).

Abstract: In a method of checking the integrity of an antenna arrangement (2) of a transmitter (1), which transmitter (1) comprises a transmitter driving stage (4) for driving the antenna arrangement (2) with a driving current (is), a first value (Isupply) indicative of the driving current (is) is determined. After that, it is detected whether the driving current (i) is outside a predefined current range by comparing the first value (Isupply) with a predefined first value range. If the first value (Isupply) is outside the first value range, then it is indicated that the antenna arrangement (2) is not in sound condition. The antenna arrangement (2) is comprised of an antenna (5) and a tuning network (6) connected between the antenna (5) and the transmitter driving stage (4).

Abstract: An electric circuit for a communication device (200) for communicating with a further communication device (500), the electric circuit comprising an inductive antenna element (101) adapted for inductively communicating with the further communication device (500), a capacitive antenna element (102) adapted for capacitively communicating with the further communication device (500), and a common matching circuit (105) adapted to match impedances of the inductive antenna element (101) and of the capacitive antenna element (102).

Abstract: In a signal processing circuit (3) for a contactlessly communicating communication partner device (1), there are provided a transmitted-signal path (9) and a received-signal path (10), the received-signal path (10) branching off from a branch point (AP) present on the transmitted-signal path (9), a filter stage (11) and a matching stage (12) connected downstream of the filter stage (11) being provided on the transmitted-signal path (9), the filter stage (11) having a resonant frequency that is in a frequency range the center frequency value of which matches an upper sideband frequency, and the branch point (AP) being situated between the filter stage (11) and the matching stage (12).

Abstract: A communication station (1) for contactless communication with at least one transponder is provided with a transmission coil configuration (2) with an active, first transmission coil circuit (21) which includes a first transmission coil (36) and with a passive, second transmission coil circuit (22) which includes a second transmission coil (42), the first transmission coil (36) as well as the second transmission coil (42) being connected to a respective central conductor (38, 50) which is connected, via a third capacitor stage (41, 53), to a connection conductor (33, 48) between two series-connected capacitor stages (31, 32 and 47, 49), the two capacitor stages (31, 32 and 47, 49) constituting capacitor means (30, 43) which are connected parallel to the relevant transmission coil (36, 42).