Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: An RFID transponder having an analog front end receiver having an attenuator coupled to receive an RF-signal from an antenna and to attenuate the RF-signal, an amplifier having a fixed amplifier gain and being coupled to receive and to amplify the attenuated RF-signal and a control unit coupled to control a gain of the attenuator, wherein the control unit is configured to control the attenuator gain in response to a level of the amplified RF-signal, the control unit is configured to have a plurality of predetermined states causing the attenuator to increase (step-up) or to decrease (step-down), its gain by a predefined step size, wherein the step size of a step-up is equal to or smaller than the step size of a step-down and wherein the control unit is further configured to switch, upon reaching or exceeding a predefined threshold value, from a first to a second state having a smaller step size and causing the attenuator to change the gain such that the slope of the RF signal inverts and to switch, upon reachi

Abstract: An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Abstract: A long-range power-efficient multiple-band identification system and method includes, for example, a base-station control module and paired electronic key fob. The base-station control module and paired electronic key fob is arranged to provide a UHF (ultra-high frequency) wake transmitter for transmitting a wakeup signal in a UHF frequency range to the paired electronic key. When in range, the electronic key is awakened by the wakeup signal and in response transmits an acknowledgment reply to the base-station control module. After receiving the acknowledgment, the base-station control module transmits a relatively high power localization signal for determining an electronic key location.

Abstract: A radio communication system includes a frequency synthesizer, a radio frequency (RF) front end, a first receiver, and a second receiver. The frequency synthesizer is configured to generate an oscillation signal, and the RF front end is configured to receive a detected RF signal and apply the oscillation signal to downconvert the RF signal to an intermediate frequency (IF) signal. More particularly, the first receiver, coupled to the RF front end, is configured to extract, from the IF signal, information wirelessly transmitted by a first RF transmitter on a first frequency channel. The second receiver, coupled to the RF front end, is configured to extract, from the IF signal concurrently with the extraction of signal information by the first receiver, information wirelessly transmitted by a second RF transmitter on a second frequency channel.

Abstract: An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Abstract: An RFID transponder is provided which includes an automatic gain control (AGC) stage for amplifying a radio frequency (RF) signal and for providing an amplified RF signal. The AGC stage has a control signal indicating an increase of the amplitude of the RF signal. A demodulator is coupled to receive the amplified RF signal for demodulating the amplified RF signal. The demodulator provides a data signal. A burst detector is coupled to receive the control signal of the AGC stage and adapted to provide a start signal in response to a change of the control signal. A wake pattern detector is coupled to receive the data signal and the start signal. The wake pattern detector is adapted to detect a predefined wake pattern in the data signal after having received the start signal and to issue a wake signal if the predefined wake pattern is detected for switching the RFID transponder from a first operating mode into a second operating mode having higher power consumption than the first operating mode.

Abstract: An electronic device and method for half duplex data transmission in a long range keyless entry and go system, and more specifically to an RFID transponder, a corresponding read/write (R/W) unit and methods for operating the RFID transponder and the R/W-unit. There is a first coil, a second coil and a third coil, being arranged as a three-dimensional antenna, a first capacitor, a second capacitor and a third capacitor couplable in parallel to the first coil, the second coil and the third coil, respectively, for selectively forming a first, a second and a third parallel-resonant circuit for receiving radio signals, a series-resonant circuit for transmitting radio signals and a control stage configured to either use one of the first, second or third parallel-resonant circuits for receiving radio signals or the series-resonant circuit for transmitting signals.

Abstract: A passive entry system receives an electromagnetic interrogation signal transmitted from an interrogation antenna to a remote transponder, wherein the interrogation signal includes a wakeup pattern data sequence. A plurality of channel signals is generated within the transponder from a corresponding plurality of antennas in response to the electromagnetic interrogation signal. Bit detection is performed on each of the plurality of channel signals to detect the wakeup pattern sequence. A received signal strength indicator (RSSI) of the interrogation signal is determined using the plurality of channel signals, wherein only channel signals on which a valid wakeup pattern sequence is detected are used for determining the RSSI. A wakeup signal is asserted to wake up a processing module in the remote transponder only when the wakeup pattern sequence is detected on at least one of the plurality of channel signals.

Abstract: A half-duplex RFID transponder with an integrated three-dimensional front-end circuit which includes three LC resonant circuits arranged in a three-dimensional configuration. Each LC resonant circuit is coupled to a different one of three storage capacitors which are charged during a capacitor charging phase by energy in an RF signal received by the associated LC resonant circuit. The front-end circuit includes three receiver channels and each receiver channel is associated to a different one of the three LC resonant circuits. A channel selector is adapted to detect, which one of the three storage capacitors is first charged to a threshold voltage, to select the receiver channel associated to the LC resonant circuit which is coupled to the storage capacitor which is first charged and to deactivate the two other receiver channels.

Abstract: An RFID transponder is provided which includes an automatic gain control (AGC) stage for amplifying a radio frequency (RF) signal and for providing an amplified RF signal. The AGC stage has a control signal indicating an increase of the amplitude of the RF signal. A demodulator is coupled to receive the amplified RF signal for demodulating the amplified RF signal. The demodulator provides a data signal. A burst detector is coupled to receive the control signal of the AGC stage and adapted to provide a start signal in response to a change of the control signal. A wake pattern detector is coupled to receive the data signal and the start signal. The wake pattern detector is adapted to detect a predefined wake pattern in the data signal after having received the start signal and to issue a wake signal if the predefined wake pattern is detected for switching the RFID transponder from a first operating mode into a second operating mode having higher power consumption than the first operating mode.

Abstract: A passive entry and immobilizer key for vehicles comprises an integrated front-end circuit (12b) with three battery-supplied receiver channels (14, 16, 18), each connected to an associated external antenna circuit with an inductor-capacitor combination (LR, CR) having a resonant frequency in the very low frequency range. The three antennas are arranged in a three-dimensional configuration. An immobilizer transponder (22) is supplied by energy received from an external transponder antenna circuit and stored in a storage capacitor (CL). The transponder antenna circuit includes an inductor-capacitor combination (LR, CR, CL) having a resonant frequency in the low frequency range. The transponder antenna circuit shares at least one inductive component (LR) with the antenna circuit of one of the three receiver channels.

Abstract: A system and method for providing a fuel dispenser with radio frequency customer identification capabilities. The system and method determines whether a transponder containing customer identification data is within range of a dispenser, the dispenser requiring activation by the customer to initiate a transaction and including a reader associated therewith for emitting radio frequency signals within the dispenser range, and for receiving customer identification data from the transponder responsive to the emitted radio frequency signals received by the transponder. When the transponder is within range of the dispenser, an in-range indication is provided to the customer. A determination is made whether the dispenser has been activated by the customer following a determination that the transponder is within the dispenser range.

Abstract: A vehicular tire pressure monitoring system, including a transponder unit (10) for each tire to be monitored, the transponder unit having an incorporated RF transmitter (12) and being physically associated with the tire to be monitored. A pressure sensor for each tire to be monitored is connected to circuitry in a corresponding transponder unit. An interrogator unit (7) is associated with each transponder unit and physically mounted on a vehicle in proximity to a wheel (9) whereon a tire to be monitored is mounted. A central RF receiver (4) for all transponder units is provided. Each transponder unit is inductively coupled with an associated interrogator unit and includes an electric charge accumulation element adapted to be charged by energy inductively supplied from the associated interrogator unit in a first mode of operation, and the charge accumulation element providing a power supply to the RF transmitter of the transponder unit in a second mode of operation.

Abstract: A power management circuit for a system that has combined power supplies from an inductively coupled circuit and from a battery comprises voltage sensing circuitry for sensing the voltage of each of the power supplies. A switching arrangement selectively connects one of the power supplies with a user or with plural users. The switching arrangement is controlled by appropriate control circuitry in response to outputs from the voltage sensing circuitry. The power management makes the best use of energy received over the inductive interface to preserve battery lifetime.