Abstract: In a radio location system for vehicles moving along a guideway, a transmitter for energizes a transponder beside the guideway. A first detector for detects a response signal from the energized transponder to determine the transponder identification. A second detector detects a positional signal received from the transponder that is decoupled from the first signal and contains precise positional information. In one embodiment, the second detector picks up a crossover signal from a crossover antenna.

Abstract: An improved system and method for monitoring objects, people, animals, or places uses a passive Modulating Reflector (MR) tag where a characteristic of an antenna is modified 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 antenna is embedded in a dielectric material. 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: A radar system is provided. The system includes a radar transceiving device equipped in a movable body and for transmitting an electromagnetic wave at a first frequency, and a transponder device arranged in a beacon and for transmitting a response wave upon receiving the electromagnetic wave. The transponder device includes a response wave transmitting module for transmitting, when a radar classification of the radar transceiving device is a solid-state radar, a response wave at a second frequency different from the first frequency in response to receiving the transmitted electromagnetic wave. The radar transceiving device includes a transmitting module for transmitting the electromagnetic wave, a receiving module for receiving a radar echo at the first frequency and the response wave at the second frequency, and a display controlling module for displaying, on a predetermined radar display unit, locations of the beacon and another movable body existing around the movable body.

Abstract: A system for response to a signal transmitted by a radar includes: a passive antenna capable of receiving and then backscattering a signal transmitted by said radar; a microwave switch connected to said antenna; at least two microwave lines each having a distinct impedance and being connected to the microwave switch; and a generator capable of generating a parametrizable control signal and sending it to the microwave switch so that it switches onto one or other of the microwave lines, so as to modulate the signal backscattered by said antenna.

Abstract: A secure communication topology can be used for communications between a locator and one or more transponders to determine the location of the transponders. An example system may include a locator that is configured to transmit an interrogation signal that is encoded for receipt by one or more of the transponders. When a transponder receives and correlates the interrogation signal with an internally stored reference sequence, the transponder can transmit one or more reply transmissions at precisely determined time delay intervals. The time delay intervals are secretly known by both the locator and the transponder. The reply transmissions can each correspond to previously sampled noise signals that are also secretly known by both the transponder and the locator.

Abstract: A system and method for monitoring and tracking the position of a subject comprises, in an exemplary embodiment, a transponder configured for being co-located with the subject and a means for enabling communication between the transponder and a remote GPS-enabled receiver, such as a cell phone or the like, for selectively triangulating the position of the transponder. In the exemplary embodiment, the means for enabling such communication is software that is installed in and executed by the receiver. The software allows the receiver to triangulate the geographic position of the transponder by fixing a first reference point based on the location of the GPS-enabled receiver, fixing a second reference point based on the location of a network broadcast site through which the receiver and transponder communicate, and calculating the location of the transponder based on the angular position of the transponder relative to the network broadcast site.

Abstract: In a synthetic aperture radar system monitoring an area containing at least one moving target for identification, the target is equipped with an identification device, which receives the radar signal transmitted by the radar system, and transmits a processed radar signal obtained by modulating the incoming radar signal with a modulating signal containing target information, such as identification and status information, and by amplifying the modulated radar signal; the radar echo signal reflected by the monitored area and containing the processed radar signal is received and processed by a control station of the radar system to locate the target on a map of the monitored area, and to extract the target information to identify the target.

Abstract: A wireless communication tag according to the present invention includes a first antenna 8 previously set with predetermined identification information, and for wirelessly communicating various types of data with a reader/writer 6; a controller (IC chip 14) for controlling the data communicated through the first antenna; a second antenna 10 for receiving an electromotive radio wave 4e for causing electric power by a radio wave; and a charging unit (rectifying circuit 16 and a capacitor 18) for causing electric power by the electromotive radio wave received from the second antenna as well as for storing the caused electric power. With use of the electric power stored in the charging unit, the first antenna supplies data relating to the identification information to the reader/writer. The second antenna also can provide the reader/writer with the identification information.

Abstract: Techniques are generally disclosed for communications between a locator device and a transponder device. The locator device may be located in a space based location such as on a surface of a remote celestial body, on a space craft or space station, on a satellite, or on a low earth orbit aircraft. The locator can encode an interrogation signal for receipt by one or more distant transponders. The transponder devices can receive the communications from the distant locator device and determine frequency, phase, cadence, and Doppler for encoding a reply transmission to the locator device. The encoding process estimates Doppler shift and adapts the reply transmission for a quantized reverse Doppler shifted frequency and cadence, which effectively pre-compensates for the Doppler shift that will be apparent to the locator due to the relative velocity. The locator can use the Doppler quantization scheme to reconstruct the actual relative velocity.

Abstract: A signal transponder for frequency conversion of signals from unknown signal sources is provided. The transponder includes an input for receiving a signal from an unknown signal source, an input filter for filtering the received signal, an input signal amplifier for amplifying the received signal, a mixer for converting the frequency of the amplified and filtered received signal to a predetermined frequency, a local oscillator for generating a clock signal supplied to the mixer for frequency conversion, an output filter for filtering the frequency converted signal, an output signal amplifier for amplifying the frequency converted signal, and an output for transmitting the filtered and amplified frequency converted signal.

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: Described are a notch antenna and an array antenna based on a low profile stripline feed. The notch antenna includes a planar dielectric substrate having upper and lower surfaces. Each surface has a conductive layer with an opening therein. A notch antenna element is disposed on the conductive layer of the upper surface at the opening. A stripline embedded in the planar dielectric substrate extends under the notch antenna element. The stripline is adapted to couple an RF signal between the stripline and the notch antenna element. A conductive via is electrically coupled to the stripline and extends from the stripline to the opening in the conductive layer on the lower surface so that the RF signal is accessible at the lower surface.

Abstract: When a lane-width-direction lateral position (X2obst+X0) of a vehicle (MM) reaches a predetermined control start position (60) being a lane-width-direction lateral position (X2obst+X0) serving as an approach prevention indicator for the vehicle (MM), a control start is determined and a yaw moment (Ms) toward the center of a vehicle traveling lane (200) is applied to the vehicle (MM) to control the vehicle (MM). Then, when the lane-width-direction lateral position (X2obst+X0) of the vehicle (MM) moves from the outside to the inside of the control start position (60), the determination of control start is suppressed for a predetermined period, compared to a period before the movement to the inside of the control start position (60).

Abstract: This document describes a method and system for object localization. In accordance with the method an object (1) is illuminated by at least one first type of signal, and response of the signal is detected. In accordance with the invention the object (1) equipped with a transponder (2, 3) backscattering the first type of signal, the transponder (2, 3) is illuminated also by a second type of signal affecting to the backscattering frequency of the transponder (2, 3), and the backscattered signal from the transponder (2, 3) is detected in order to localize the object.

Abstract: An apparatus, which may be configured as a receiver or transceiver, includes a plurality of super regenerative (SR) amplifiers coupled in parallel, wherein the SR amplifiers are tuned to distinct frequency bands, respectively. The apparatus may further include isolation amplifiers at the respective inputs and outputs of the SR amplifiers to prevent injection locking and reduce power leakage. The apparatus may include a circuit to reduce or substantially eliminate in-band jamming signals. The apparatus may form at least part of a wireless communications device adapted to receive signals from other wireless communications devices, adapted to transmit signal to other wireless communications devices, and adapted to both transmit and receive signals to and from other wireless communications devices.

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: 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: An aircraft avian radar is implemented using an existing aircraft transponder, Mode S, or TCAS installation as the radar transmitter. To eliminate self jamming of low level avian target signals by high level transmitter signals, the ending period of the transmission signal is digitized and cross correlated with the ending period of reflected avian target signals received after the transmission signal has ended. In a first implementation, the current transponder antenna is used for both transmission and reception. In a second implementation, an external receive only antenna is mounted in a position that maximizes the transmit antenna to receive antenna isolation. In a third implementation, a signal canceller and sample of the transmit signal are used to cancel or null out as much transmit signal as possible that couples directly to the receive antenna.

Abstract: A chipless microwave identification tag (200) comprising: a dielectric substrate (210); and a plurality of antenna elements (220) made from a conductive material and disposed on at least one surface (205, 255) of the dielectric substrate (210); wherein when the tag (200) is excited by an incident microwave signal (131), a reflected wave (141) to identify the tag (200) is generated with a number of specific frequencies altered by microwave resonation of the antenna elements (220).

Abstract: An application specific integrated circuit chip includes capacitors and antennas. The antennas receive energy from an outside source, and charge capacitors on the chip in order to provide power to the chip itself. The chip in turn communicates by antenna to outside receivers for the purposes of identification of the chip and hence a bag or article to which it is attached. The chip is attached to its article by means of glue which is in turn applied by an applicator which shoots the chip and the glue against the article.

Abstract: Distance to a modulated backscatter tag is measured with a RFID reader that measures changes in phase with frequency of modulated backscattered RF signals. Measured distances are linked to a specific tag. The effects of other sources of reflected and interfering signals are mitigated. The techniques eliminate the need for high RF bandwidth used in time-of-flight methods, and may be used with linear, limiting or other types of amplifiers in the reader receiver. Unambiguous distance to a tag may be found using the derivative of phase with RF frequency of the modulated signal backscattered by a tag. The distance to a tag can be measured with an accuracy on the order of a centimeter. The techniques utilize the characteristics of cooperative backscatter tags (transponders, labels, etc.). New readers implement the techniques which may use unmodified tags.

Abstract: A method and apparatus for validating a distance output of a phase ranging RFID location system, based upon the phase readings included in data sets obtained from monitoring reply signals corresponding to interrogation signals at multiple frequencies and a common interrogation signal beam direction; by comparison of measured phase and frequency data sets with theoretical phases calculated with respect to the same frequencies over a range of positions corresponding to a beam extent of the interrogation signal. The distance output validated by comparison with theoretical threshold data processed to generate an extreme values distribution from which a cumulative distribution function is extracted and against which a confidence level is applied.

Abstract: Method, systems, and articles of manufacture for assigning priority to antenna are disclosed. In accordance with a preferred embodiment of the invention, reader antenna (151, 152, 153) identify the location of an object by detecting a tag or other identifier associated with each object. Sensors (121, 122, 123) can be provided to provide additional information regarding the environment of the objects to their surroundings. A priority order is assigned to the reader antenna based on the location and other characteristics of the objects and/or their environment. A polling sequence for reading the reader antennae is determined according to the priority order.

Abstract: There is provided a method for identifying, at the moment of verification, the situation of a threat to a protected ground, airspace and/or sea limits by an approaching ground vehicle, aircraft or sea-going vessel. The method includes an authorized driver/pilot/captain to select first state in which the vehicle, aircraft or sea-going vessel is not considered to present a threat and a second state in which the vehicle, aircraft or sea-going vessel is considered to present a threat. The method further provides entering the first and second PIN codes into a smart card for generating a One Time Indicia (OTI) for each of the PIN codes and disclosing the state associated with each of the first and second OTI codes to at least one control center. Upon the control center receiving an OTI code, the control center obtains positive identification of the driver/pilot/captain and the degree of the threat that the vehicle, aircraft or sea-going vessel presents.

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 system is provided for identifying implanted medical devices, leads and systems, as well as objects in close proximity to a patient having an implanted active medical device, using a radio frequency identification (RFID) tag having retrievable information relating to the AIMD, lead system and/or patient. An RFID tag communicator includes a circuit for limiting the total continuous transmit time of an interrogation signal, and a time-out circuit for delaying a second and any subsequent interrogation of the RFID tag.

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 method for wireless data communication between a base station and at least one transponder by a high-frequency electromagnetic carrier signal, onto which information packets are modulated, wherein each information packet has a header section, a middle section, and a terminating end section, wherein the middle section has a data field, which contains the data necessary for the data communication, wherein at least one additional control field is inserted into the data field by which the structure of the information packets can be variably adjusted within the region of the data field. The invention relates further to a transponder, a base station, and a data communication system.

Abstract: A transponder (12) transmits a reply in response to an interrogation input thereto, the interrogation including twin pulses, and a monitoring processor (13) transmits to the transponder a pseudo interrogation identical in format to the interrogation, receives from the transponder a reply responding to the pseudo interrogation, and monitors a performance of the transponder, the monitoring processor (13) including a pulse spacing adjuster (131c) operable to adjust a pulse spacing of twin pulses along with generation of the pseudo interrogation, and a monitor (134b) operable to output an alarm in response to a failed reception or a delayed reception of a reply from the transponder after transmission of a pseudo interrogation with a compliant pulse spacing, and further to output an alarm in response to a reception of a reply from the transponder after transmission of a pseudo interrogation with an uncompliant pulse spacing.

Abstract: To provide a wireless communication method in the case where communication of a wireless signal from a communication device to a semiconductor device can be ensured, communication of a wireless signal can be ensured without using a repeater even when communication of a wireless signal from a semiconductor device to a communication device is difficult due to an external factor such as an obstacle. A plurality of semiconductor devices operate in selectively switching between a first state in which the first wireless signal transmitted from the communication device is received and a second state in which the second wireless signal transmitted from the semiconductor device is received. The semiconductor device in the second state receives the second wireless signal from the semiconductor device in the first state and transmits to the communication device the second wireless signal including detection data for indicating that the second wireless signal is received.

Abstract: A method and system for monitoring one or more objects by an electronic device are provided. The method includes defining a distance threshold between the electronic device and an object having a RFID tag, calculating a distance between the electronic device and the object, and generating alerts upon detecting that the distance is greater than the distance threshold.

Abstract: To provide a wireless IC tag which is readable even in a plurality of countries (destination countries) using different radio frequency bands for reading. The wireless IC tag of the present invention is characterized by comprising: a case (20); an antenna (60), which is provided in the case (20); a metal plate (901), which is disposed in the case opposite to the antenna (60); and a mechanism for altering the resonance characteristics of the wireless IC tag (10) by moving at least one of the antenna (60) and the metal plate (901) in the case (20), thereby altering the distance (D) between the metal plate (901) and the antenna (60). With such wireless IC tag (10), the capacitance of an equivalent tuning capacitor consisting of the antenna (60) and the metal plate (901) can be arbitrarily altered by a distance alteration unit, and thereby, the resonance characteristics of the wireless IC tag (10) can be altered in accordance with the frequency band of reading radio wave used by a reader/writer.

Abstract: An aircraft system includes a transponder and a processor. The processor is configured to determine if the aircraft is positioned in a predetermined restricted flying zone. If the aircraft is positioned in a predetermined restricted flying zone, the processor determines if the transponder is functioning in a transmit mode. If the transponder is not functioning in a transmit mode, the processor sets the transponder to function in a transmit mode.

Abstract: The present disclosure is directed to systems and methods for providing attenuation alerts for a radar-based terrain warning. A method for providing radar-based terrain warning attenuation alerts may comprise: (a) receiving a radar return; (b) detecting a region of atmospheric disturbance limiting the range of the radar return; and (c) providing a notification of radar-based terrain awareness warning system attenuation in the region of atmospheric disturbance.

Abstract: A method for determining a physical property of a structural member in a dynamic multi-path clutter environment is given. The method comprises transmitting an RF interrogation signal to a wireless sensor operable to receive the RF interrogation signal, produce a reference signal and a measurement signal, and transmit the reference signal and the measurement signal in the dynamic multi-path clutter environment. The reference signal is delayed by a first time delay and the measurement signal is delayed by a second time delay that is a function of the physical property to be determined. The first and second time delays are associated by a known relationship defined by the wireless sensor. The method further comprises receiving the transmitted reference signal and the transmitted measurement signal and comparing the transmitted reference signal and the transmitted measurement signal in the time domain. Finally, the method comprises using this comparison to determine the physical property of the structural member.

Abstract: In radar transponder operation, a variably delayed gating signal is used to gate a received radar pulse and thereby produce a corresponding gated radar pulse for transmission back to the source of the received radar pulse. This compensates for signal distortion due to amplitude modulation on the retransmitted pulse.

Abstract: A backscatter transponder for an HF communication system with modulated reradiation, is provided that includes an antenna for receiving high-frequency carrier signals, wherein the antenna has reflective characteristics, a control unit for providing transponder-specific parameters, and a modulator that can be driven by the control unit. The modulator altering the reflective characteristics of the antenna in accordance with at least one transponder-specific parameter.

Abstract: An identification system which may be employed in a transport or monitoring system has at least one stationary and at least one mobile transmission unit which are each provided with an antenna, which antennas in turn are coupled inductively or capacitively to each other during the transmission of data. At least one of the antennas is designed such that in response to a mutual displacement of the coupled antennas a direction-dependent modulation of the transmitted signals occurs which is demodulated and evaluated in at least one of the transmission units, for example, by a demodulation unit and a processor, optionally a signal processor, in order to obtain information relating to the relative motion of the two transmission units. In addition to known identification functions, the identification system may perform additional important functions without requiring any significant additional expense.

Abstract: A radar target identification apparatus utilizing a pseudo-random digital code to modulate a target's return signal to include a two-dimensional range and cross range Doppler-coded return with a target's skin return and thereby identify friendly targets to the interrogating radar unit.

Abstract: When multiple readers for RF transponders have to be placed in close proximity, such as in adjacent lanes of a highway toll barrier, they can be set to operate at different frequencies. When signals from two adjacent ones of the readers interfere, the resulting signal includes interference terms whose frequencies equal the sum of the reader frequencies and the difference between the reader frequencies. To remove such interference terms while passing the desired terms, a tag includes a low-pass or other frequency-selective filter.

Abstract: An RF transponder includes an input circuit, a read/memory circuit, and a circuit arrangement for holding a control state. The circuit arrangement includes a first storage device (e.g. a D-flip-flop) for storing the control state dependent on received control signals, and a second storage device (e.g. a capacitor and a transistor) for holding the control state during a period of inadequate energy supply to the circuit arrangement, e.g. while the transponder is in a field gap of the electromagnetic field emitted by a base station with which the transponder communicates. In an operating method, the control state is held by the second storage device during a period of inadequate energy supply. Then, when adequate energy is again supplied, the transponder resumes the control state that was held by the second storage device. The transponder continues to operate properly according to an anti-collision procedure in a system of several transponders communicating individually with a base station.

Abstract: An apparatus for an enhanced receiver for an RFID Tag Interrogator is described. The enhanced receiver has a zero crossing detector, a phase shifter, a pulse generator and a chopper. The zero crossing detector produces a sampling signal from the current transformer. The phase shifter modifies the sampling signal by producing a 90 degree phase shifted sampling signal. The pulse generator increases time duration of each pulse of the phase shifted sampling signal, which is then fed to the chopper. Thus, the chopper samples the backscattered carrier signal every 90 degree phase shift from the time when the backscattered carrier signal passes the zero crossing. This makes isolation of the backscattered signal from the carrier signal more effective.

Abstract: An integrated circuit chip includes a rectifier circuit configured to convert an alternating voltage supplied from an antenna into a direct-current voltage, a nonvolatile memory coupled to the rectifier circuit to operate by use of the direct-current voltage, a sensor circuit coupled to the rectifier circuit to operate by use of the direct-current voltage to collect measurement data, and a logic circuit configured to control the nonvolatile memory and the sensor circuit such that an access operation of the nonvolatile memory and a data collecting operation of the sensor circuit are not performed concurrently.

Abstract: An oscillation maintenance circuit for a half-duplex transponder that has an LC resonant circuit, a storage capacitor and a rectifier connected to charge the storage capacitor with a rectified oscillation signal, having an end-of-burst detector providing an end-of-burst signal when the amplitude of the oscillation signal has dropped below a predetermined threshold. A clock regenerator provides a clock signal derived from the oscillation signal. Switching means controlled by the clock signal in the presence of the end-of-burst signal connect the storage capacitor with LC resonant circuit through at least one current limiting resistor during part of the period of the clock signal, in such a manner that energy is fed into the LC resonant circuit.

Abstract: Communication between a remote locator and a transponder is used to determine the relative position of the transponder. The transponder and locator each include a transmitter and a receiver. The locator transmits an inquiry in the form of a relatively powerful cyclically encoded signal with repetitive elements, uniquely associated with a target transponder. Periodically, each transponder correlates its coded ID against a possible inquiry signal, determining frequency, phase and framing in the process. Upon a match, the transponder transmits a synthesized response coherent with the received signal. The locator integrates multiple cyclical response elements, allowing low-power transmissions from the transponder. The locator correlates the integrated response, determines round-trip Doppler shift, time-of-flight, and then computes the distance and angle to the transponder. The transponder can be wearable, bionically implanted, or attached to, or embedded in, some object.

Abstract: A system for identifying radio-frequency identification (RFID) devices is described. In one embodiment, RFID devices include an antenna and metallic pattern printed on a substrate. A probing platform is used to radiate the RFID devices with an electromagnetic signal (e.g., radio-frequency signal, microwave signal, etc.). Each RFID device generates a quantifiable backscatter depending on the unique impedance of the passive RFID device in response to the electromagnetic signal. The backscatter is employed to uniquely identify the passive RFID device's impendence with respect to the probing platform uniquely characterized at predetermined frequencies of the electromagnetic signal.

Abstract: There are presented various approaches to monitor performance of RF systems and circuitry such as those used in aircraft transponders. Such monitoring may be designed to verify operational performance of transponders as set forth by FAA regulations, or may be used to periodically or continually monitor integrity of transponder performance. Data may be collected by such periodic or continual monitoring, and may be analyzed to identify potentially troublesome trends in transponder performance, allowing early intervention or repair, if warranted.

Abstract: A radar transponder which does not have a receiver/transmit switch. A radio frequency coupler of the transponder switches the antenna between the transmitter and the receiver. The coupler connects the receiver, the transmitter and the antenna such that the receiver is connected to the most attenuated terminal of the coupler. The coupler may be a radio frequency coupler having an attenuation of between three and forty dB, or approximately ten dB. The antenna can be an integrated PCB surface-mounted multi-bay turnstile antenna.

Abstract: An electromagnetic transponder comprising: an oscillating circuit; a first rectifying bridge having its A.C. input terminals connected across the oscillating circuit and having its rectified output terminals connected at least to a voltage regulator in charge of providing a supply voltage; and a second rectifying bridge, of dimension smaller than that of the first bridge, having its two A.C. input terminals connected across the oscillating circuit and having at least one output terminal connected to a demodulator of data sensed by the oscillating circuit.

Abstract: An RFID transponder comprises an antenna for receiving data in a downlink mode and transmitting data in an uplink mode, with a modulation stage for modulating uplink data and a demodulation stage for demodulating downlink data. A class C amplifier is provided, which has a resonant circuit, a plucking device coupled to the resonant circuit, and a controllable pulse width generator coupled to the plucking device. The controllable pulse width generator is adapted to periodically switch the plucking device on and off so as to maintain an oscillation of the resonant circuit. The transponder further comprises a phase locked loop configured to be locked to an oscillating signal received through the antenna and to be switched into a free running mode without being locked to the oscillating signal received through the antenna, thereby being adapted to output an independent internal clock signal for the RFID transponder.