Abstract: Systems and methods are provided for a capacitive inventory sensor. A system includes a track configured for retaining items. A first conducting plate is positioned along a portion of the track, and a second conducting plate is positioned in parallel with the first conducting plate along a portion of the track. The second conducting plate is positioned a distance from the first conducting plate, and the second plate is configured to have the items placed on top of the second plate. The system further includes a capacitance sensor configured for connection to the first and second conducting plates, where the capacitance sensor is configured to measure a capacitance between the first and second conducting plates, and where the capacitance varies based on a number of items positioned on the sensor track.

Abstract: Systems and methods are provided for a low stock product display alert system. A system includes a pushing element configured to push one or more products toward a front of a shelf as a unit of the product is removed from the shelf. The system also includes an RFID component, where the RFID component is configured to be in a dormant state when the pushing element is in a first position. The system further includes an activation element configured to activate the RFID component when the pushing element is in a second position, where when activated, the RFID component is configured to emit a signal indicating that the product display is out of product.

Abstract: Systems and methods are provided for a low stock product display alert system. A system includes a pushing element configured to push one or more products toward a front of a shelf as a unit of the product is removed from the shelf. The system also includes an RFID component, where the RFID component is configured to be in a dormant state when the pushing element is in a first position. The system further includes an activation element configured to activate the RFID component when the pushing element is in a second position, where when activated, the RFID component is configured to emit a signal indicating that the product display is out of product.

Abstract: Systems and methods are provided for a capacitive inventory sensor. A system includes a track configured for retaining items. A first conducting plate is positioned along a portion of the track, and a second conducting plate is positioned in parallel with the first conducting plate along a portion of the track. The second conducting plate is positioned a distance from the first conducting plate, and the second plate is configured to have the items placed on top of the second plate. The system further includes a capacitance sensor configured for connection to the first and second conducting plates, where the capacitance sensor is configured to measure a capacitance between the first and second conducting plates, and where the capacitance varies based on a number of items positioned on the sensor track.

Abstract: Systems and methods are provided for a low stock product display alert system. A system includes a pushing element configured to push one or more products toward a front of a shelf as a unit of the product is removed from the shelf. The system also includes an RFID component, where the RFID component is configured to be in a dormant state when the pushing element is in a first position. The system further includes an activation element configured to activate the RFID component when the pushing element is in a second position, where when activated, the RFID component is configured to emit a signal indicating that the product display is out of product.

Abstract: Systems and methods are provided for a low stock product display alert system. A system includes a pushing element configured to push one or more products toward a front of a shelf as a unit of the product is removed from the shelf. The system also includes an RFID component, where the RFID component is configured to be in a dormant state when the pushing element is in a first position. The system further includes an activation element configured to activate the RFID component when the pushing element is in a second position, where when activated, the RFID component is configured to emit a signal indicating that the product display is out of product.

Abstract: Systems and methods are provided for monitoring a plurality of RFID tags. A receiver selection signal is sent along a receive path that includes a plurality of serially connected receivers. A receiver relays the receiver selection signal, listens for an RFID response signal, or operates in a standby mode based on the receiver selection signal. A transmitter selection signal is sent along a transmit path that includes a plurality of serially connected transmitters. A transmitter relays the transmitter selection signal, transmits an identification impulses, or operates in a standby mode based on the transmitter selection signal. The identification impulse is transmitted from the selected transmitter and an RFID response signal is received at the selected receiver.

Abstract: Systems and methods are provided for monitoring a plurality of RFID tags. A system includes a plurality of serially connected transmitters along a transmit path, where each of the serially connected transmitters are configured to relay a received transmitter selection signal when the transmitter selection signal identifies a selected transmitter as being further along the transmit path than the serially connected transmitter and transmit an identification impulse using a transmit antenna when the transmitter selection signal identifies the serially connected transmitter as being the selected transmitter. A system further includes a control unit responsive to a plurality of transmit paths, the control unit being configured to send the transmitter selection signal along a selected transmit path, where the transmitter selection signal identifies one of the plurality of serially connected transmitters along the selected transmit path as the selected transmitter for transmitting the identification impulse.

Abstract: Systems and methods are provided for a capacitive inventory sensor. A system includes a track configured for retaining items. A first conducting plate is positioned along a portion of the track, and a second conducting plate is positioned in parallel with the first conducting plate along a portion of the track. The second conducting plate is positioned a distance from the first conducting plate, and the second plate is configured to have the items placed on top of the second plate. The system further includes a capacitance sensor configured for connection to the first and second conducting plates, where the capacitance sensor is configured to measure a capacitance between the first and second conducting plates, and where the capacitance varies based on a number of items positioned on the sensor track.

Abstract: A battery operated device includes a receiver for receiving a transmission that includes a postamble. A sensor, in a tire, measures a parameter of the tire and outputs data indicative of the parameter. A microprocessor is coupled to the receiver and the sensor. The microprocessor is configured to periodically partially awaken to determine whether the transmission is likely a forward link packet (FLP) by examining the postamble, and to transmit the data in a reverse link packet (RLP) in response to confirming that the transmission is a FLP.

Abstract: A battery operated device includes a receiver for receiving a transmission that includes a postamble. A sensor, in a tire, measures a parameter of the tire and outputs data indicative of the parameter. A microprocessor is coupled to the receiver and the sensor. The microprocessor is configured to periodically partially awaken to determine whether the transmission is likely a forward link packet (FLP) by examining the postamble, and to transmit the data in a reverse link packet (RLP) in response to confirming that the transmission is a FLP.

Abstract: Systems and methods are provided for a low stock product display alert system. A system includes a pushing element configured to push one or more products toward a front of a shelf as a unit of the product is removed from the shelf. The system also includes an RFID component, where the RFID component is configured to be in a dormant state when the pushing element is in a first position. The system further includes an activation element configured to activate the RFID component when the pushing element is in a second position, where when activated, the RFID component is configured to emit a signal indicating that the product display is out of product.

Abstract: A battery operated device includes a receiver for receiving a transmission that includes a postamble. A sensor, in a tire, measures a parameter of the tire and outputs data indicative of the parameter. A microprocessor is coupled to the receiver and the sensor. The microprocessor is configured to periodically partially awaken to determine whether the transmission is likely a forward link packet (FLP) by examining the postamble, and to transmit the data in a reverse link packet (RLP) in response to confirming that the transmission is a FLP.

Abstract: A distributed antenna array with a centralized data hub for determining the presence and location of RF tags has been disclosed. This antenna array centralizes electronics and distributes the RF to zones in a facility to greatly reduce the expense of recurring components for monitoring RF tags. A single BRT/hub with multiple antennas attached to transmit and receive ports is used to cover an entire facility. Large facilities are covered by a small number of the BRT/hub combinations. The BRT/hub has transmit antennas coupled thereto, preferably by co-axial cable, that transmit signals to a portion or all of the RF tags and all or a portion of them modulate and reflect the RF signal to a particular receiving antenna. The receiving antenna then returns the RF signal with tag data to the BRT/hub, preferably by co-axial cable. Also disclosed is an RF backscatter tag that cleanly switches a resonant aperture antenna on and off, thereby greatly increasing the mark-to-space ratio of the backscatter data.

Abstract: A high power amplifier having an automatic gain control circuit, the high power amplifier being coupled between the output end of an RF signal carrying coaxial cable and a transmitting antenna to automatically compensate for RF signal attenuation over the length of the coaxial cable.

Abstract: Systems and methods are provided for monitoring a plurality of RFID tags. A system includes a plurality of serially connected transmitters along a transmit path, where each of the serially connected transmitters are configured to relay a received transmitter selection signal when the transmitter selection signal identifies a selected transmitter as being further along the transmit path than the serially connected transmitter and transmit an identification impulse using a transmit antenna when the transmitter selection signal identifies the serially connected transmitter as being the selected transmitter. A system further includes a control unit responsive to a plurality of transmit paths, the control unit being configured to send the transmitter selection signal along a selected transmit path, where the transmitter selection signal identifies one of the plurality of serially connected transmitters along the selected transmit path as the selected transmitter for transmitting the identification impulse.

Abstract: Systems and methods are provided for monitoring a plurality of RFID tags. A receiver selection signal is sent along a receive path that includes a plurality of serially connected receivers. A receiver relays the receiver selection signal, listens for an RFID response signal, or operates in a standby mode based on the receiver selection signal. A transmitter selection signal is sent along a transmit path that includes a plurality of serially connected transmitters. A transmitter relays the transmitter selection signal, transmits an identification impulses, or operates in a standby mode based on the transmitter selection signal. The identification impulse is transmitted from the selected transmitter and an RFID response signal is received at the selected receiver.

Abstract: A system for conserving battery life in a battery operated device such as a tire tag where there are several modes of operation. The typical mode is the deep sleep mode where the tag is generally inactive (no clock is running; however, an RC watchdog timer is running, which uses very little power). The tag spends most of its time in this low power mode. The tag periodically partially awakens to a lucid sleep mode (when the watchdog timer times out), initiates a low-speed clock, determines if it is time to enter a search mode by examining a search mode counter and, if it is not time, adjusts the search mode counter (e.g., decrements the counter by one), and returns to the deep sleep mode. The tag sleeps in the deep sleep mode most of its life in an effort to conserve battery power. During the deep sleep mode, because the clock oscillators are OFF, a deep sleep counter is adjusted (incremented or decremented) periodically (e.g., about every 18 ms) by an internal R/C oscillator.

Abstract: A battery operated device includes a receiver for receiving a transmission that includes a postamble. A sensor, in a tire, measures a parameter of the tire and outputs data indicative of the parameter. A microprocessor is coupled to the receiver and the sensor. The microprocessor is configured to periodically partially awaken to determine whether the transmission is likely a forward link packet (FLP) by examining the postamble, and to transmit the data in a reverse link packet (RLP) in response to confirming that the transmission is a FLP.

Abstract: In accordance with the teachings described herein, RFID systems are provided that include a distributed RFID antenna array utilizing one or more circular polarized helical antennas. A plurality of RFID tags may be used, with each RFID tag including a linear polarized antenna for communicating RFID tag signals. One or more receiver antennas may be used for receiving the RFID tag signals from the RFID tags. An RFID tag signal reader may be used to process RFID tag signals received by the receiver antennas. In one example, the receiver antennas may include a circular polarized helical antenna element. One or more transmitter antennas may be used for transmitting an RF signal to the plurality of RFID tags, the transmitter antennas including a circular polarized helical antenna element. A transmitter may be used to generate the RF signal for transmission by the transmitter antennas. In one example, the RFID tag signal reader and the transmitter may be included in a single reader/transmitter unit.