Abstract: A circularly polarized antenna includes a generally helical wire defining a generally cylindrical passage having a first end and a second end. A first ground plane is proximate the first end of the generally cylindrical passage and has a width substantially equal to a diameter of the generally cylindrical passage. A cable extends through the generally cylindrical passage and is electrically coupled to the first ground plane and to the generally helical wire proximate the first end.

Abstract: This disclosure discloses methods and apparatus for detecting and characterizing radio-frequency identification (RFID) tags.

Abstract: A wireless encoder for encoding a plurality of wireless communication devices carried by media comprises a shielded enclosure having an exterior surface defining an aperture; a wireless signal generator to excite the shielded enclosure; and a media path along which media carrying a plurality of wireless communication devices travels. The media path passes across the aperture outside the shielded enclosure.

Abstract: In systems and methods for determining the placement of radio-frequency identification (RFID) tags, a tag reader communicates with one or more RFID tags at different locations of a target object. The tag reader determines which of the different locations is a preferable location for placing an RFID tag by detecting the transmission power level or other value required to communicate with the RFID tag at each of the different locations.

Abstract: A radio frequency identification (RFID) reader outputs an interrogation signal, and hops/varies the phase of the interrogation signal sent by the RFID reader over time. Varying the phase of the interrogation signal enables the RFID reader to provide, for each zone of an RF field of the RFID reader, a particular phase that reduces of the effects of interference RF signal(s) present in that zone of the RF field. Reducing the interference in each zone of the RF field increases the throughput of RFID tags that can be successfully read by the RFID reader.

Abstract: Spatial antenna diversity is used with RFID tags to reduce sensitivity to multi-path fading. RFID tags can use a single multi-port chip or multiple multi-port chips. The ports of the chip or chips are coupled to separated feedpoints on one or more antennas.

Abstract: Systems, methods, and devices wirelessly communicate in a near-field region and a far-field region. A device may include a near-field antenna and a far-field antenna. The device may be configured to selectively operate in a near-field mode, employing the near-field antenna, and/or in a far-field mode, employing the far-field antenna, and/or in a joint mode, employing both the near-field antenna and the far-field antenna separately or concurrently. One type of device may be a wireless communications data-reader device configured for both near-field and far-field communications. Another type of device may be a wireless communications data-provider device configured for both near-field and far-field communications.

Abstract: A compact flexible high gain antenna is disclosed which includes a co-planar array of at least three substantially parallel main conducting antenna elements, a reflector, a driven element, and a director. Each of these elements may be terminated on the ends by a stub element, and the reflector and the director may include an intermediate meander element. Stub elements capacitively load the antenna, while meander elements inductively load the antenna, and the loading affects the resonant frequency of the antenna. The conducting antenna elements may be affixed to a flexible dielectric substrate and may be bent or curved into different compact shapes, suitable for fitting manufacturing form factors for a handheld RFID reader. The antenna has a high directional gain which results in a longer operating range.

Abstract: A media marking transponder system includes a media fastener and a wireless transponder circuit coupled to the media fastener. The antenna for the wireless transponder circuit has a first effective length when no piece of media is fastened to the media fastener and a second, different effective length when at least one piece of media is fastened to the media fastener.

Abstract: Data carriers (such as RFID tags) are formed into clusters of data carriers. Each cluster has at least one bridge data carrier that can communicate with a bridge data carrier of another cluster, thereby allowing data carriers in each cluster to communicate directly or indirectly with each other using a stochastic communication protocol method. Direct tag-to-tag communication capability is provided between data carriers in each cluster and/or between clusters. The data carriers can backscatter and modulate a carrier wave from a source, thereby using the backscattered and modulated carrier wave to convey data to each other.

Abstract: A media processing apparatus includes a self-calibrating encoding assembly that send read/write inquires to determine appropriate power levels for encoding encodable objects. The apparatus includes a control subsystem that tracks the power levels of the encoding assembly and the corresponding positions of media carrying the encodable objects. The controller then determines an encoding window and an encoding power level at which the encoding assembly encodes an encodable object in the encoding power window without unwanted communication to encodable objects outside of the window.

Abstract: A radio frequency identification (RFID) tag is adapted to operate with a wideband or multiple band of frequencies, such as 860-960 MHz. The RFID tag includes a flexible antenna inlay structure that can be integrated into a rigid structure to form a rigid RFID tag. The antenna inlay structure can be folded to provide a compact rigid RFID tag. The antenna inlay structure may also be used in a smart label. The antenna inlay structure can work with RFID chips operating under Gen 2, ISO, or other protocol. The RFID tag can be provided with a metallized label that operates to shield the antenna inlay structure against electromagnetic effects of an object (such as a metallic object) having the RFID tag affixed thereon.

Abstract: Systems and methods for increasing the range of RFID tags are provided. A supplemental RF power source can be provided to energize the tag and increase the distance at which an RFID tag can be read by an RFID reader. In some embodiments, the supplemental power source can be provided at a substantially constant wavelength. In other embodiments, the supplemental power source can be provided by a frequency hopping transmitter or other variable wavelength source.

Abstract: A multi-band and/or multi-protocol, configurable, RFID tag is provided. The tag can include one or more electrical or mechanical selectors for selecting from among multiple frequency bands and communication protocols. In some embodiments, a signal band and protocol can be detected automatically and selection among bands and protocols can be performed automatically. In some embodiments, one or more externally accessibly switches can be actuated by a user to select a band and/or protocol.

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: Wireless remote control may omit batteries. A carrier wave from an external carrier wave source may be modulated and backscattered with information identifying a user selection. The backscattered modulated carrier wave response may be received and interpreted for controlling one or more electronic devices.

Abstract: A wireless, batteryless microphone includes an antenna and passive circuitry to backscatter a carrier wave signal modulated with audio information from a sound transducer. A wireless, batteryless speaker or headphone includes an antenna and passive circuitry to drive a sound transducer based on a received modulated carrier wave. A headset may include a wireless, batteryless microphone and one or more wireless, batteryless speakers or headphones.

Abstract: A radio frequency identification system comprises a radio-frequency identification substrate and an interrogator. In one embodiment, the radio-frequency identification substrate comprises a plurality of radio-frequency identification devices. In one embodiment, a controller on the substrate controls a first one of the plurality of radio-frequency identification devices based on a state of a second one of the plurality of radio-frequency identification devices. In one embodiment, an antenna system includes an S-shaped portion electrically coupled to an integrated circuit along a central portion of the S-shaped portion. Adjusting the parameters of the segments making up the S-shaped portion controls performance characteristics of a radio-frequency identification device.

Abstract: An automatic data collection system reads data encoded in data carriers located inside enclosed environments, such as radio frequency identification (RFID) tags attached to objects located in enclosures, such as buildings, shipping containers, transportation vehicles such as airplanes, and other enclosures. The enclosures have dimensions that normally exceed the read range of the RFID tags, and/or the enclosures are composed of a material (such as metal) that impede communication of signals with external RFID readers. Therefore, internal antenna systems are provided inside of the enclosures to relay interrogation signals from RFID readers to the RFID tags, and to relay response signals from the RFID tags back to the RFID readers.

Abstract: A radio frequency identification (RFID) tag includes an antenna having a shape providing a machine-readable or human-readable code or symbol. For example, a machine-readable code may comprise a bar code, or other suitable optical code. Human-readable symbols may include, for example, text, alpha-numeric symbols, icons, or pictographs. Using human-readable antenna forms, an RFID tag may be used as a label, for example, to add a distinctive look to the tagged product, to further identify the tag or product it is attached to, or for branding the tag or attached product.