Abstract: The present disclosure describes a system, methods and apparatus for determining a direction of motion of an RFID tag. An RFID reader is provided that includes an antenna that is tilted at a tilt angle with respect to a detection path. Response signals from the RFID tag are received at the antenna at different times, and an RSSI sample of each response signal is measured. Based on the RSSI samples, an RSSI/time data point is generated for each of the RSSI samples. Each RSSI/time data point defines a measured RSSI value for a particular RSSI sample versus a time that particular RSSI sample was measured. Based on the plurality of RSSI/time data points, the direction of motion of the RFID tag can be determined.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: A dual polarization antenna system includes a dipole antenna oriented along a first plane (e.g., a horizontal plane), and a monopole antenna oriented along a second plane (e.g., a vertical plane) orthogonal to the first plane, wherein the monopole antenna is referenced to a V-null point of the dipole antenna.

Abstract: An antenna includes a dipole radiator region forming a series resonant tank having a first quality factor value Q1, and a loop compensator/radiator region integral with the dipole region and forming a parallel resonant tank having a second quality factor value Q2 that is substantially equal to Q2. The antenna may be a conductive sheet antenna (e.g., comprising copper tape) having a generally “A” shaped structure with a discontinuity in a middle segment.

Abstract: Described herein are methods, devices and systems for characterizing an attached antenna to an electronic device, such as a radio frequency identification (“RFID”) reader. One exemplary embodiment is related to a method comprising outputting a low amplitude modulation (“AM”) index radio frequency (“RF”) waveform, the waveform simulating tag data timing and bandwidth, removing a direct current (“DC”) component from the waveform to create a chopped portion of the waveform, applying at least one vector analyzer technique on the chopped portion of the waveform, characterizing at least one antenna impedance vector of the waveform.

Abstract: An antenna for using within an allocated bandwidth having a nominal center frequency includes a support member, a first antenna structure, and a second antenna structure. The first antenna structure has a return loss maximized at a first optimal frequency. The second antenna structure has a return loss maximized at a second optimal. The difference between the first optimal frequency and the second optimal frequency is more than 10% of the allocated bandwidth but less than 100% of the allocated bandwidth.

Abstract: Described is a device including a processor, a wireless arrangement including an antenna, and a memory arrangement storing first data and second data. The first data includes predetermined antenna characteristics and the second data includes predetermined triggering characteristics for triggering a function of the device. When third data fails to match the first data, the processor compares the third data to the second data, the third data being indicative of characteristics changes of the antenna. The processor triggers a corresponding function of the device as a function of the third data and the second data.

Abstract: The present invention is directed to systems that use frequency selective surfaces (FSS) to aid in the operation of radio frequency identification (RFID) devices and products. In one embodiment, a system for interrogating radio frequency identification (RFID) tags includes a conveyor belt and an RFID reader. The conveyor belt has a first surface and a second surface. The first surface is configured to receive an item to which an RFID tag is affixed and the second surface is configured to slide on a metal slide plate. The RFID reader is configured to transmit instructions embodied in a radio frequency (RF) signal to the RFID tag, wherein the metal slide plate is positioned between the RFID reader and the RFID tag and comprises a frequency selective surface that is substantially transparent to the RF signal.

Abstract: Described herein are devices, systems and methods for compensating a frequency response of an antenna to an electronic device, such as a radio frequency identification (“RFID”) reader. An exemplary embodiment is a device including at least one radio frequency (“RF”) source for transmitting RF signals, at least one RF receiver for receiving RF signals, an antenna in simultaneous communication with the RF source and the RF receiver, and at least one distributed RF compensator network controlling an operating RF between the antenna and the communication device, wherein the at least one distributed RF compensator creates a particular antenna impedance that operates with a directional coupler and increases an RF isolation between the RF source and the RF receiver across a particular frequency region.

Abstract: A dual-mode RFID reader is capable of automatically switching from a far-field interrogation mode to a near-field interrogation mode upon the detection of certain operating or handling conditions. The RFID reader includes an RFID radio module configured to support a far-field interrogation mode and a near-field interrogation mode, an antenna arrangement coupled to the RFID radio module, and a mode-switch sensor architecture coupled to the RFID radio module. The mode-switch sensor architecture is configured to detect conditions indicative of near-field interrogation, and the RFID radio module automatically configures itself for operation in the near-field interrogation mode upon detection of such conditions.

Abstract: Methods, systems and apparatuses for RFID readers forming a reader network are described. In an aspect of the present invention, a plurality of RFID readers are configured to interrogate tags. Furthermore, the readers are configured to communicate with one another by transferring a token, represented by a signal. Possession of the token enables the reader to access a RF communications medium. Readers can be arranged in a ring configuration, and interconnected via wired links. A secondary token may circulate in the ring in addition to the primary token, to ensure redundancy in the system. A reader waits for a predetermined time interval before accessing the RF communications medium.

Abstract: A method for improving RFID readers includes transmitting an outgoing RF signal to an antenna through a directional device, and generating a demodulated vector signal from an RF signal related to the RF signal received from the receiver. The method also includes setting the impedance of a controllable-variable-reflectance element with control-parameters from a memory circuit. The memory circuit includes a look up table having therein a corresponding relationship between the control-parameters and an error vector related to the demodulated vector signal.

Abstract: Methods, systems, and apparatuses for a reader transceiver circuit are described. The reader transceiver circuit incorporates a frequency generator, such as a surface acoustic wave (SAW) oscillator. A reader incorporating the reader transceiver circuit is configured to read a tag at very close range, including while being in contact with the tag. The transceiver can be coupled to various host devices in a variety of ways, including being located in a RFID reader (e.g., mobile or fixed position), a computing device, a barcode reader, etc. The transceiver can be located in an RFID module that is attachable to a host device, can be configured in the host device, or can be configured to communicate with the host device over a distance. The RFID module may include one or more antennas, such as a first antenna configured to receive a magnetic field component of an electromagnetic wave and a second antenna configured to receive an electric field component of an electromagnetic wave.

Abstract: Described are a device and a method for canceling a magnetic field and/or an electric field emitted from a device. The device includes a housing including an inner wall and an outer wall, a sense coil located within the inner wall of the housing in proximity to a user's ear, the sense coil sensing a magnitude, polarization and a polarity of an inbound magnetic field within the housing, and an induction coil located between the outer wall and the inner wall of the housing, the induction coil generating an outbound magnetic field having the same polarization and an opposing polarity to the polarity of the inbound magnetic field. The method includes sensing, by a sensing coil, a magnitude and a polarity of an inbound magnetic field, the sensing coil located within a housing of a device, and applying a current to an induction coil to generate an outbound magnetic field having an opposing polarity to the polarity of the inbound magnetic field, the induction coil located within the housing of the device.

Abstract: Methods, systems, and apparatuses for a reader transceiver circuit are described. The reader transceiver circuit incorporates a frequency generator, such as a surface acoustic wave (SAW) oscillator. A reader incorporating the reader transceiver circuit is configured to read a tag at very close range, including while being in contact with the tag. The transceiver can be coupled to various host devices in a variety of ways, including being located in a RFID reader (e.g., mobile or fixed position), a computing device, a barcode reader, etc. The transceiver can be located in an RFID module that is attachable to a host device, can be configured in the host device, or can be configured to communicate with the host device over a distance. The RFID module may include one or more antennas, such as a first antenna configured to receive a magnetic field component of an electromagnetic wave and a second antenna configured to receive an electric field component of an electromagnetic wave.

Abstract: Methods, systems, and apparatuses for providing power to devices that are part of RFID systems are described. Energy is harvested at portable/mobile devices, stored and conditioned to provide on-going power as needed for various circuits/components. The energy may be generated in a variety of ways, including using a vibratory energy harvesting device, a magnetic energy harvesting device, and an optical energy harvesting devices.

Abstract: An RFID portal is enhanced to provide communication capability to RFID communication enabled devices. Such devices include cameras, PDAs, voice communicator, keyboards, displays, indicators, storage devices, etc. Devices are made RFID communication enabled by providing them with an RFID interface and an RFID tag “front end”. Such an enhanced device communicates with an enhanced portal via an RFID reader/interrogator associated with the portal. The portal may have connection to other communication channels, such as an Ethernet tie to a network, a landline phone connection, a cellular interface, an 802.11 connection, a Bluetooth channel, etc. Such connections allow an RFID communication enabled device to communicate beyond the enhanced portal to the outside world.

Abstract: A wearable mobile computer communicates with a headset worn by an operator using a communication channel established between the computer and a radio frequency identification (“RFID”) tag located in the headset. The headset may be configured for receive only (voice travels only from the computer to the headset) or configured for two-way voice communication. For two-way communication backscatter from the RFID tag is used to carry voice signals.

Abstract: Methods, systems, and apparatuses for RFID devices, such as reader antennas, are described. A reader antenna includes a quadrature hybrid coupler, a termination element, and an antenna, such as a patch antenna. The quadrature hybrid coupler has first, second, third, and fourth ports. The first port receives an input radio frequency RF signal. The second port outputs a first RF output signal. The third port outputs a second RF output signal. The second RF output signal is shifted in phase by 90 degrees relative to the first RF output signal. The fourth port is coupled to the termination element. The patch antenna has a first point coupled to the first RF output signal and a second point coupled to the second RF output signal. The patch antenna radiates a circularly polarized RF signal due to the received first and second RF output signals. The circularly polarized RF signal may be used to interrogate tags.