Abstract: A method of manufacturing a transponder for a wireless card includes forming an antenna coil on a film sheet, short-circuiting both end portions of the antenna coil by a short-circuit portion, mounting an LSI on the film sheet, electrically connecting a terminal of the LSI to both ends of the antenna coil, and removing the short-circuit portion after the LSI is mounted.

Abstract: An adaptive inductive ballast is provided with the capability to communicate with a remote device powered by the ballast. To improve the operation of the ballast, the ballast changes its operating characteristics based upon information received from the remote device. Further, the ballast may provide a path for the remote device to communicate with device other than the adaptive inductive ballast.

Abstract: A vehicle detector includes a detecting apparatus and a determining apparatus. If a plurality of detection points detected by the detecting apparatus forms a group of detection points, the determining apparatus sets a determining virtual window encompassing the group of detection points and determines whether the group of detection points is likely to represent the one vehicle based on a state of movement of the group of detection points with respect to the determining virtual window.

Abstract: A system and method for monitoring topological changes in a defined area. A grid of sensors is arranged in the area, with known distances between them. The sensors communicate wirelessly with a host computer, which individually addresses each sensor to instruct that sensor to be in an interrogate mode or responder mode. When a sensor is in interrogate mode, it measures distance from a neighboring sensor using radar (continuous wave phase difference) measurements. When a sensor is in responder mode, it receives, delays, and returns a signal received from a neighboring sensor.

Abstract: A system for ascertaining the range from an interrogator to one or more transponders comprises an interrogator that transmits an RF carrier that is received by each transponder, the energy in the received carrier being used to charge up a storage capacitor in each senses the termination of the received carrier and initiates a known delay interval different from those of the other transponders. At the end of the delay interval, the transponder transmits an RF signal which is received by the interrogator. The interrogator then calculates the range to the transponder by subtracting the known delay interval from the round trip time registered in the timer.

Abstract: The invention relates to a system, device, and method for using radar signals to measure the distance (h) to a surface from said device, the device comprising a transmitter and a transmitting antenna for transmitting radar signals, and a receiver and a receiving antenna for receiving a radar signal. The device may also comprise a first additional reflecting object separate from the receiving antenna, which additional reflector is designed so as to introduce a first predetermined alteration in radar signals upon reflection, with the device being equipped with means to differ between received signals with and without said predetermined alteration. The first predetermined alteration introduced by the first separate reflector can be, for example, a modulation shift or a shift in the polarization of the signal. In a typical embodiment the additional reflector is located close to the radar unit creating a double transition from radar unit to the surface.

Abstract: An improved system and method for monitoring objects, people, animals, or places uses a passive Modulating Reflector (MR) tag where an antenna is alternately short and open circuited according to a time-varying pattern by a modulating network thereby causing the reflective characteristics of the antenna to vary in accordance with the time-varying pattern. When an interrogator transmits an RF waveform that impinges on the antenna, the return signal reflecting off the antenna is modulated in accordance with the time-varying pattern allowing a remote receiver to demodulate information from the modulated return signal. The MR tag can be used with a wide variety of tag-interrogator configurations employing monostatic and/or bistatic radar techniques to allow monitoring, locating, and/or tracking of objects, people, animals, or place with which MR tags are associated.

Abstract: There are provided a differential processing unit which performs differential processing for a Mode S transponder transmission signal, an auto correlation arithmetic operation unit which performs an arithmetic operation of a degree of auto correlation between an increasing change rate and decreasing change rate of a power level in the signal which has been subjected to the differential processing, a pulse regeneration unit which regenerates a pulse based on the degree of auto correlation, which has been obtained by the auto correlation arithmetic operation processing, a pulse phase locked loop unit which performs gate processing and phase locked processing for the regenerated pulse, and a pulse decoding unit which decodes the Mode S transponder transmission signal based on the pulse which has been subjected to the gate processing and the phase locked processing.

Abstract: Interfering clutter in radar pulses received by an airborne radar system from a radar transponder can be suppressed by developing a representation of the incoming echo-voltage time-series that permits the clutter associated with predetermined parts of the time-series to be estimated. These estimates can be used to estimate and suppress the clutter associated with other parts of the time-series.

Abstract: A wireless, in particular mobile, communication device (8) for communicating with communication units (9) in vehicles (5, 6, 7), comprising a transmitter (26) and a receiver (29) for information-containing electromagnetic waves, as well as a control unit (25) for controlling the transmitter (26), a directional characteristic (10, 10?) being provided for the receiver (29) and/or for the transmitter (26), for a selective communication with communication units (9) in vehicles (5, 6, 7) at distances (D) of more than 10 m, preferably in the order of from 20 m to 200 m, e.g. in the order of approximately 100 m, in particular with a receiving angle, or a radiation angle, respectively, of from 0.5° to 4°, preferably 0.8° to 2.5°, and a sighting unit (13) as well as an indication unit (16, 18) being provided, the indication unit being connected with the receiver (29) via a processing unit.

Abstract: The present invention is a combined aircraft TCAS/Transponder with common antenna system and transmitter. Common TCAS/Transponder multi-monopole top and bottom antennas may be connected to a top and bottom antenna modules, the top and bottom antenna modules being electrically coupled to the combined TCAS/Transponder transmitter/receiver block through connection lines.

Abstract: A transmitter provides a plurality of output signals. The transmitter includes a processor, a modulator, a first circuit, and a second circuit. The modulator provides a modulated signal responsive to the processor. The modulated signal includes an amplitude modulated radio frequency for transmitting a pulse. The first circuit provides a first output signal, responsive to and with higher power than the modulated signal. The first output signal has a first phase during transmitting of the pulse. The second circuit provides a second output signal, responsive to and with higher power than the modulated signal. The second output signal has a second phase during transmitting of the pulse. The second phase is controlled by the second circuit in accordance with the first phase, the second phase, and indicia of a third phase provided by the processor.

Abstract: An apparatus for use in controlling a simulated target position in a millimeter wave, hardware-in-the-loop system includes a pair of horns and a conditioning circuit. The conditioning circuit is capable of generating a pair of output millimeter wave signals, each to be broadcast from a respective one of the horns, the output millimeter wave signals being out of phase by a predetermined amount, and capable of attenuating at least one of the output millimeter wave signals to control the position of the simulated target in a first and a second region. A method for use in controlling a simulated target position in a millimeter wave, hardware-in-the-loop system includes generating a pair of output millimeter wave signals that are out of phase by a predetermined amount; attenuating at least one of the output millimeter wave signals to control the position of the simulated target in a first and a second region; and broadcasting the millimeter wave signals.

Abstract: An apparatus for use in controlling a simulated target position in a millimeter wave, hardware-in-the-loop system includes a pair of horns and a conditioning circuit. The conditioning circuit is capable of generating a pair of output millimeter wave signals, each to be broadcast from a respective one of the horns, the output millimeter wave signals being out of phase by a predetermined amount, and capable of attenuating at least one of the output millimeter wave signals to control the position of the simulated target in a first and a second region. A method for use in controlling a simulated target position in a millimeter wave, hardware-in-the-loop system includes generating a pair of output millimeter wave signals that are out of phase by a predetermined amount; attenuating at least one of the output millimeter wave signals to control the position of the simulated target in a first and a second region; and broadcasting the millimeter wave signals.

Abstract: An RF transponder comprises a transponder integrated circuit, an antenna connected to the transponder integrated circuit, and at least one parasitic element adapted to interact electrically with the antenna and thereby affect antenna impedance. The orientation of the parasitic element with respect to the antenna is selected to achieve a desired operational frequency band for the RF transponder. Specifically, the spacing between the antenna and the parasitic element is selected to achieve the desired operational frequency band. For example, a first selected spacing may enable an operational frequency band suitable for a first geographic region (e.g., the United States), a second selected spacing may enable an operational frequency band suitable for a second geographic region (e.g., Europe), and a third selected spacing may enable an operational frequency band suitable for a third geographic region (e.g., Japan).

Abstract: An IDT produces a SAW when excited by a single electrical pulse and can be fabricated to embody a code, which code provides for a passive autocorrelation of a SAW input to the IDT and thereby lends itself to further application as a signal generator in a communication device. However, internal dimensions of IDTs are inversely proportional to operating frequency, such that high frequency IDTs present significant manufacturing difficulties. Fabrication of IDTs for high frequency applications is simplified by exploiting a harmonic frequency SAW generated by IDTs. An IDT may therefore be designed according to fundamental frequency internal dimension criteria but can operate at a multiple of the fundamental frequency, thereby providing much higher frequency operation than conventional SAW systems. Operation of a second harmonic SAW system at 2.4 GHz based on a fundamental frequency of 1.2 GHz is contemplated.

Abstract: Transponders, receivers and position determining systems are described. In one embodiment, a transponder includes (i) an on-board receiver and associated receiving antenna for receiving incoming radar pulses in a first frequency band at an unknown pulse repetition rate, (ii) means for calculating the pulse repetition rate, (iii) a frequency synthesizer for generating a signal in a second frequency band, (iv) modulation means for modulating the signal generated by the frequency synthesizer so as to encode information into the signal, and (v) a transmitter and associated transmitting antenna for transmitting said modulated signal, wherein the transmitted signal is synchronized with the calculated pulse repetition rate of the incoming radar pulses, and modulation of the transmitted signal is such that accurate positioning of the transponder can be determined at a remote receiver.

Abstract: A system comprises a radar for producing a radar interrogation signal, a transponder for receiving the radar interrogation signal and producing a transponder signal including a first linear frequency modulated pulse having an increasing frequency and a second linear frequency modulated pulse having a decreasing frequency, and a processor for processing the transponder signal to determine a frequency offset between the radar interrogation signal and the transponder signal.

Abstract: A system and method for performing distance measurement using wireless signals. A time of flight calculation is enabled by an interrogating device that transmits an interrogation signal to a responding device, which returns a synchronized signal back to the interrogating device. The wireless signals between the interrogating device and the receiving device have a harmonic relationship. In one embodiment, a time shift of a received signal relative to a transmitted interrogation signal is determined based on a comparison of a first reference point on a signal representative of the transmitted interrogation signal and a second reference point on a signal representative of the received signal.

Abstract: A vehicle positioning and tracking radar system includes a rotating antenna with a pair of spatially separated transmit feeds for simultaneously transmitting a pair of frequency-modulated continuous-wave (FMCW) electromagnetic signals having a first polarisation and a pair of spatially separated receive feeds for receiving an electromagnetic signal having a second polarisation, wherein the first and second polarisations are different from one another, such that the transmit feed and receive feed at the rotating antenna are isolated from each other; and a coded modulated transponder receives transmit signals from the rotating antenna with the first polarization and transmits a receive signal to the rotating antenna with the second polarization.

Abstract: A radio frequency identification device includes an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: An interrogator with an antenna that allows information exchanges with multiple transponders in a shorter distance of communication, by securing an intensified and uniform electromagnetic energy concentrated on areas near antenna elements. The interrogator is furnished with a sleeve antenna that includes a monopole conductor of ¼ wavelength (free space wavelength) continuously connected to a core wire of a coaxial cable on one end thereof, and a feed point on the other end, in which the sleeve antenna is grounded at the feed point. The interrogator has a plurality of the transponders arrayed near the antenna, and a plurality of the antennas selected by RF signal selectors. The interrogator antenna allows movable body identification such as in a goods management system for identifying multiply arrayed goods.

Abstract: System and method for transparently attaching wireless peripherals to a computer using a Bluetooth wireless network. A preferred embodiment comprises an interface (for example, interface 630), a communications bus (for example, a USB 620), and a Bluetooth wireless network adapter (for example, a master unit 610). The interface translates messages from either the communications bus or the Bluetooth wireless network adapter so that a software stack is not needed to perform the translation at a later time. This helps to maintain the computer's reliability and performance. The system and method also affords wireless connectivity without the presence of a computer system.

Abstract: A SAW communication device has a main IDT mounted on an SAW substrate to receive an RF signal received by an antenna and convert the RF signal to an acoustic wave which travels along the SAW substrate in opposite directions from the main IDT. At least two secondary IDTs are mounted on the SAW substrate on opposite sides of and spaced from the main IDT to receive and reflect the acoustic wave in a modulated form such that the modulated acoustic wave from one secondary IDT is delayed relatively to the modulated acoustic wave from a secondary IDT on the opposite side of the main IDT to the one secondary IDT. The main IDT is also operable to receive and convert the reflected modulated acoustic waves to a further RF signal with a concatenated waveform corresponding to the two modulated acoustic waves and transmit the further RF signal from the antenna.

Abstract: An RF tag is provided to communicate with an interrogating source in which the tag has programmability and flexibility to uplink data to multiple platforms. As such the RF tag functions as a miniature programmable transceiver capable of communicating with a plurality of different platforms each having different waveform characteristics. With well-controlled spectral characteristics due to stored waveforms and the use of specialized direct digital up and down conversion techniques, data rates up to 256 kbps are achievable. The tag is thus capable of converting microwave signals directly to digital inputs, and the transmitter generates microwave signals directly from digital outputs. Flexible digital processing also allows a throughput of 900 BOPS when using field programmable gate arrays.

Abstract: A radio frequency device has an antenna for capturing an incoming signal for processing by the device or for radiating an outgoing signal from the device and a signal processor having one or more synchronous oscillators responsive to an input signal for providing an amplified output signal without using much power. An application is a radio frequency (RF) transponder (tag) for receiving an RF signal from an interrogator includes a tag antenna for receiving the RF signal from the interrogator and a receiver section connected to the tag antenna wherein the receiver consumes a significantly lower amount of power than conventional receiver technologies by using one or more synchronous oscillators.

Abstract: A surface acoustic wave sensor or identification device has a piezoelectric material, and an interdigitated transducer (IDT) input/output mounted on the piezoelectric material for receiving a radio frequency (RF) signal and propagating a corresponding surface acoustic wave along a surface of the piezoelectric material. An IDT finger electrode array is mounted on the piezoelectric material and is operable to communicate with the IDT input/output for transmission of a modified RF signal from the device. The IDT finger electrode array has at least one finger electrode segment whose propagating characteristics are controlled to control the nature of the modified RF signal. A biolayer is mounted on the piezoelectric material and is associated with the finger electrode segment, and a fluidic chamber is associated with the biolayer.

Abstract: The invention relates to an IFF apparatus for ground applications, which comprises: (a) an encoder for forming an interrogating or response sequence of pulses, and conveying the same to a UWB transmitter; (b) an UWB transmitter for getting said interrogating or response sequence of pulses, forming a corresponding interrogating or response signal of a sequence of UWB pulses, and transmitting the same via a UWB transmitting antenna; (c) a plurality of UWB receiving antennas, disposed away one from the other, for receiving either an interrogating signal or a response signal sent by another IFF apparatus; (d) a decoder for getting from at least one of said UWB receiving antennas received signals, decoding the same, comparing the decoded signal with a bank of pre-stored signals, and determining whether a received signal is an interrogating or response signal; and (e) a processing unit for, upon receipt of a signal of response to an interrogation signal sent by the present IFF apparatus, calculating the location of

Abstract: A radar transponder is provided that synchronizes the encoding of repeated radar pulses using an envelope detector to detect the envelope of received radar pulse signals. An edge detector detects the pulse edges in the envelope so that code words may be multiplied with the received radar pulse signals synchronously with the detected pulse edges to provide an encoded pulse train that may be transmitted to a radar interrogator.

Abstract: A wireless network transmits digital data. The network includes an active transceiver to transmit carrier waves at a succession of preselected frequencies and a transponder. The transponder transmits digital data to the active transceiver by partially reflecting the carrier waves.

Abstract: An apparatus for detecting position information of a moving object. The apparatus includes a transponder, a communication module, and a reader. The transponder is installed on a predetermined location of a road and stores position information associated with the installed location. The communication module is mounted to a moving object, emits an RF (Radio Frequency) signal toward a road surface, and receives position information associated with the transponder's installation location from the nearest transponder using an RF signal. The reader receives position information associated with the transponder's installation location from the communication module, and reads a current position of the moving object. The apparatus minimizes a data error between the detected position information. The transponder installed on a road is driven by RF signals received from external devices, resulting in increasing a lifetime of the transponder.

Abstract: Methods and systems reduce clutter interference in a radar-responsive tag system. A radar transmits a series of linear-frequency-modulated pulses and receives echo pulses from nearby terrain and from radar-responsive tags that may be in the imaged scene. Tags in the vicinity of the radar are activated by the radar's pulses. The tags receive and remodulate the radar pulses. Tag processing reverses the direction, in time, of the received waveform's linear frequency modulation. The tag retransmits the remodulated pulses. The radar uses a reversed-chirp de-ramp pulse to process the tag's echo. The invention applies to radar systems compatible with coherent gain-block tags. The invention provides a marked reduction in the strength of residual clutter echoes on each and every echo pulse received by the radar. SAR receiver processing effectively whitens passive-clutter signatures across the range dimension. Clutter suppression of approximately 14 dB is achievable for a typical radar system.

Abstract: A far field radio frequency identification (RFID) tagging and tracking system employing a plurality of continuous wave (CW), unmodulated signals selected from frequencies including a predetermined frequency band, includes a RFID interrogator generating a group of CW unmodulated signals corresponding to a RFID tag and receiving a tag identification (ID) signal sequence uniquely identifying the RFID tag, while the RFID tag includes a power source supplying power to the RFID tag but not including a microprocessor. A corresponding RFID tag and method for operating both the tag and the system are also described.

Abstract: A system and method for interrogating a passive acoustic transponder, producing a transponder signal having characteristic set of signal perturbations in response to an interrogation signal, comprising a signal generator, producing an interrogation signal having a plurality of differing frequencies; a receiver, for receiving the transponder signal; a mixer, for mixing the transponder signal with a signal corresponding to the interrogation signal, to produce a mixed output; an integrator, integrating the mixed output to define an integrated phase-amplitude response of the received transponder signal; and an analyzer, receiving a plurality of integrated phase-amplitude responses corresponding to the plurality of differing frequencies, for determining the characteristic set of signal perturbations of the passive acoustic transponder.

Abstract: A Mode-S transponder is provided for detecting synchronization phase reversal (SPR) signals. The transponder includes a receiver for receiving a Mode-S signal that contains a P6 pulse having a Mode-S data segment and an SPR signal therein. The transponder also includes a phase detector that detects a phase change between first and second states in the received Mode-S signal. The phase detector includes an SPR qualifier that determine whether, following a state change, the Mode-S signal remains at one of the first and second states for at least a predetermined minimum time sufficient to qualify as a detector enable signal.

Abstract: A transponder having a subsystem for providing an altitude alert function signifying a deviation from a set altitude is described. The subsystem includes an input for receiving an altitude deviation limit associated with the set altitude, a CPU receiving updated altitude and determining a difference between the updated altitude and the set altitude associated with the altitude deviation limit, and a transponder subsystem output device for providing the difference between the updated altitude and the set altitude to a user.

Abstract: A SAW RFID tag or sensor has an antenna for receiving and propagating an RF signal, an input/output IDT electrically connected to the antenna, and a dual track reflective IDT having a first track and a second track located adjacent and acoustically coupled to the input/output IDT. An RF signal received from the antenna by the input/output IDT is transformed by the input/output IDT into an acoustic way which is propagated to the dual track IDT. One track of the dual track IDT is in-phase with the phase reference of the input/output IDT and the other track is in quadrature phase with said phase reference. The input/output IDT receives two orthogonal complex modulated acoustic waves reflected from the first and second tracks and transforms them to a modulated orthogonal complex RF signal which is propagated from the antenna.

Abstract: A surface acoustic wave sensor or identification device has a piezoelectric substrate, an interdigitated transducer (IDT) input/output mounted on a substrate for receiving a radio frequency (RF) signal and propagating a corresponding surface acoustic wave along a surface of the substrate. An IDT reflector array is mounted on the substrate and operable to receive a surface acoustic wave and reflect the surface acoustic wave in modified form back to the IDT input/output for transmission of a corresponding modified RF signal from the device. The IDT reflector array has at least one reflector segment whose reflectivity characteristics are controlled to control the nature of the modified RF signal.

Abstract: An enhanced backscatter RF-ID tag reader system and multiprotocol RF tag reader system is provided. In a multiprotocol mode, the system emits a non-stationary interrogation signal, and decodes a phase modulated backscatter signal by detecting a stronger phase component from quadrature phase representations or determining phase transition edges in a phase of a received signal. The RF tag reader system predicts or follows the phase of the backscatter signal, thereby avoiding interference from nulls in the received signal waveform due to the non-stationary interrogation signal, relative movement or environmental effects. An acoustic RF-ID tag detection system detects the reradiated signal corresponding to respective transformation of a signal in the tag. Detection of either type of RF-ID tags therefore is possible, and the absence of any tag or absence of any valid tag also determined.

Abstract: In a transponder (19) for amplification of a received signal (60) into an antenna (1), to a signal (61) for retransmission, and where the retransmitted signal (61) possibly may have information superimposed, a quenched oscillator (5) is incorporated as amplifying element. The oscillator (5) is preferably of superregenerative type and exhibits negative resistance (30) for the received signal (60). Transponders according to the present invention may be introduced as system elements in a wireless or wire based network to work as intelligent or unintelligent connections in the network. The transponders can also be used in positioning systems.

Abstract: A data carrier (1) for contactless communication with the communication station comprises firstly a reception stage (3) for receiving an interrogation signal (IS), secondly a generation stage (17) for generating a response signal (RS) upon reception of the interrogation signal (IS), thirdly a processing circuit (18) for processing the response signal (RS) into a transmission signal (MCRS) suitable for transmission to the communication station, fourthly a determination device (22) for determinating at least one representative value (REP1, REP2), the representative value (REP1, REP2) representing the field strength of the field acting on the data carrier (1), and fifthly a control connection (25) between the determination device (22) and the processing circuit (18), wherein the processing circuit (18) is influenced via the control connection (25) in order to vary a transmission parameter of a transmission signal generated by the processing circuit (18) as a function of the at least one representative value (REP

Abstract: An access control system for an object, particularly a motor vehicle, comprises at least one base station with a transceiver device that transmits a wideband modulated interrogation signal, at least one transponder that has a modulation device, in order to modulate an auxiliary carrier signal, the frequency of which is changed between an infinite number of frequency positions, onto an interrogation signal received at a distance from the base station and reflect it as a code-modulated response signal, and an evaluation device that is connected after the transceiver device and that evaluates the response signal in sidebands of the changed frequency positions, with respect code and distance.

Abstract: A Write Broadcast system and method uses a base station to write sent data to all or some selected number (sub group) of tags in a base station field simultaneously. By unselecting the tags that have been successfully written to, and requesting a response from the remaining tags in the field (or sub group), the system determines, by receiving a response to the request, that there are tags in the field (sub group) that were unsuccessfully written to. Another Write Broadcast signal is sent to these tags. The system is useful for quickly (simultaneously) “stamping” information on the tag memory of a large number of tags in the field of the base station.

Abstract: Methods and corresponding apparatus to recover data from a signal comprising groups of pulses generated in response to analog waveforms are described. Data recovery in accordance with the invention is based on parameters characterizing the groups of pulses. These parameters are the basis for mapping the groups of pulses to information symbols which collectively constitute the data to be recovered.

Abstract: A system for providing the identification and tracking of motor vehicles that includes a probe device that transmits a radio frequency modulated signal to a transponder unit that is located within a vehicle registration tag of a vehicle. The transponder unit responds to the probe unit's request by transmitting its own radio frequency modulated signal containing any information requested by the probe device.

Abstract: A receiving/backscattering arrangement for carrying out a contactless data transmission includes an integrated circuit having two antenna contacts, a series arrangement of three high quality capacitances connected between the two antenna contacts, whereby the middle capacitance is an MOS varactor, a controllable variable voltage source connected across the MOS varactor, and a control unit that controls the voltage source. The receiving/backscattering arrangement is especially a passive transponder with a rectifier connected between the antenna contacts, or a semi-passive transponder including a battery or solar cell, to provide the required supply voltage for the circuit. The arrangement achieves a large communication range, for receiving and modulating an interrogation signal, and backscattering the modulated response signal with a high efficiency and low losses. The integrated circuit structure is compact and economical.

Abstract: A transceiver or transponder particularly for synthetic aperture radar, or SAR, systems, operating in a frequency band having a central frequency, the transponder comprising a receiver (1) and a transmitter (2) both thermally stable and made by microstrip technology, the receiver (1) and the transmitter (2) being adapted to receive and to transmit, respectively, an electromagnetic wave provided with at least one linear polarisation, the receiver (1) being connected to the transmitter (2) by amplifier means comprising an amplifier unit (5) for each linear polarisation of the wave received by the receiver (1), each amplifier unit (5) including at least two amplifier stages (7, 9, 11) cascade arranged along a single microstrip and interconnected to one another and to an input and to an output of the corresponding amplifier unit (5) by means of coupling or matching stages (6, 8, 10, 12), the output signal of each amplifier unit (5) having substantially the same frequency as the input signal thereto, the amplifier

Abstract: An RFID transponder is provided with an active backscatter amplifier that amplifies and re-transmits a received signal. The RFID transponder comprises an antenna and a circulator having a first port connected to the antenna. A modulator is connected to a second port of the circulator. An amplifier is connected to a third port of the circulator, with the amplifier connected to the modulator. An RF signal impinging upon the antenna passes through the circulator, the amplifier, and the modulator, and returns to the antenna through the circulator. The modulator further comprises an input coupled to the second port of the circulator and an output coupled to an input of the amplifier. The amplifier has an output coupled to the third port of the circulator. The modulator is adapted to modulate the RF signal using on-off keying.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.

Abstract: A radio frequency identification device comprises an integrated circuit including a receiver, a transmitter, and a microprocessor. The receiver and transmitter together define an active transponder. The integrated circuit is preferably a monolithic single die integrated circuit including the receiver, the transmitter, and the microprocessor. Because the device includes an active transponder, instead of a transponder which relies on magnetic coupling for power, the device has a much greater range.