Abstract: The present disclosure is directed to a system and method for multiplexing radio frequency signals. In some implementations, a system includes a host coupling module, a plurality of antennas, and a processing module. The host coupling module is configured to receive and transmit RF signals through a wired connection. The plurality of antennas are configured to wirelessly transmit RF signals and receive RF signals from RFID tags. The processing module is configured to selectively switch between the plurality of antennas for communication with the RFID tags using the host coupling module and backscatter at least a portion of the received RF signals through the wired connection to communicate information independent of an internal power supply.

Abstract: The present disclosure is directed to a system and method for converting between different radio frequencies. In some implementations, a method includes receiving a request from a Radio Frequency Identification Device (RFID) reader configured to communicate with a first type of RFID tag. Independent of digital signal processing, the received request is automatically converted to a request compatible with a second type of RFID tag different from the first type of RFID tag. The converted request is transmitted to an RFID tag of the second type of RFID tag.

Abstract: The present disclosure includes a system and method for conducting radio frequency signals using multiple layers. In some implementations, a signal transfer element configured to passively transfer RF signals between a first region and a second region includes a first conductor layer having a first continuous conductor configured as a first portion of a first antenna, a transmission line, and a first portion of a second antenna. The first antenna and the second antenna are configured to wirelessly receive and transmit Radio Frequency (RF) signals. The signal transfer element also includes a second conductor layer having a second continuous conductor configured as a second portion of the first antenna, a ground plane, and a second portion of the second antenna.

Abstract: The disclosure includes a system and method for oversampling and digitally filtering RFID signals. In some implementations of the present disclosure, an RF receiver includes an ADC, a comb filter, and a mask filter. The ADC is operable to directly sample an RF signal independent of a band pass filter and convert the RF signal to a digital signal. The RF signal is sampled at a rate greater than or equal to 60 MHz. The comb filter is coupled to the ADC. The mask filter is coupled to the comb filter. The comb filter and frequency mask filter are configured to filter out-of-band noise in the digital signal.

Abstract: The present disclosure is directed to a system and method for backscattering different radio frequency protocols. In some implementations, a radio Frequency (RF) tag includes an antenna and a storage module. The antenna is configured to receive an RF signal from any of a plurality of readers. Each reader is associated with a different protocol having different time durations. The storage module is coupled to the antenna and configured to store energy associated with the RF signal. In addition, the storage module substantially maintains a voltage in the tag during any of the different time durations independent of an internal power supply.

Abstract: The present disclosure is directed switching RFID tags. In some implementations, the RFID system includes an RFID tag and a panel. The panel includes one or more contacts configured to move between a first position and a second position. The second position forms an electrical connection between the RFID tag and the one or more contacts to update a state of the RFID tag.

Abstract: The present disclosure includes a system and method for reducing leakage noise in directly sampled radio frequency signals. In some implementations, a Radio Frequency IDentification (RFID) reader includes an antenna, an Analog-to-Digital Converter (ADC), a synthesizer module, and a Carrier Noise Reduction (CNR) module. The antenna is configured to receive Radio Frequency (RF) signals and pass the RF signals to a receive path. The ADC is configured to directly sample RF signals in the receive path in accordance with a clock signal and generate a digital signal. The synthesizer module is configured to generate the clock signal and a signal used to upconvert a transmitter signal. The clock signal and the upconversion signal are phase locked. The CNR module is configured to reduce leakage noise in the receive path.

Abstract: The present disclosure is directed to determining speeds of radio frequency tags. In some implementations, a method includes sampling a Radio Frequency (RF) signal from an RFID tag at a plurality of different times as the RFID tag approaches an RFID reader and recedes from the RFID reader. A phase of the RF signal is determined for each of the plurality of different times based, at least in part, on the sampled RF signal. A speed of the RFID tag is determined based, at least in part, on the determined phase for the sampled signal for each of the plurality of different times.

Abstract: A method and system for tracking each item in a cluster of items. Each item has an associated item ID. The method and system involve the following steps. Storing a plurality of item records. The plurality of item records includes, for each item in the cluster of items, an associated item record for storing the associated item ID for the item. Each item record in the plurality of records is then linked to the other item records in the plurality of item records. Using the associated item record for each item in the threshold number of items, and the link between each item record and the other item records, the item records for the associated item ID of each item in the cluster that are not in the threshold number of items are determined.

Abstract: The present disclosure is directed to a system and method for multiplexing radio frequency signals. In some implementations, a system includes a host coupling module, a plurality of antennas, and a processing module. The host coupling module is configured to receive and transmit RF signals through a wired connection. The plurality of antennas are configured to wirelessly transmit RF signals and receive RF signals from RFID tags. The processing module is configured to selectively switch between the plurality of antennas for communication with the RFID tags using the host coupling module and backscatter at least a portion of the received RF signals through the wired connection to communicate information independent of an internal power supply.

Abstract: The present disclosure includes a system and method for passively transferring radio frequency signals. In some implementations, a signal transfer element configured to passively transfer RF signals between a first region of a container and a second region of the container includes a first antenna, a second antenna and a coaxial transmission line. The first antenna is configured to wirelessly receive and transmit RF signals and passively transfer wirelessly received RF signals to a first end of a coaxial transmission line. The second antenna is configured to wirelessly receive and transmit RF signals and passively transfer wirelessly received RF signals to a second end of the coaxial transmission line. The coaxial transmission line is configured to passively transfer RF signals between the first antenna and the second antenna.

Abstract: The present disclosure includes a system and method for conducting radio frequency signals using multiple layers. In some implementations, a signal transfer element configured to passively transfer RF signals between a first region and a second region includes a first conductor layer having a first continuous conductor configured as a first portion of a first antenna, a transmission line, and a first portion of a second antenna. The first antenna and the second antenna are configured to wirelessly receive and transmit Radio Frequency (RF) signals. The signal transfer element also includes a second conductor layer having a second continuous conductor configured as a second portion of the first antenna, a ground plane, and a second portion of the second antenna.

Abstract: The present disclosure is directed to a system and method for tracking tampered with RFID tags. In some implementations, an RFID tag includes a tearable substrate including at least a portion of an RFID circuit. The portion of the RFID circuit is substantially destroyable in response to at least an attempt to remove the tag from a surface. In addition, the RFID includes an adhesive layer adjacent at least a portion of the tearable substrate and configured to affix the tag to the surface.

Abstract: The present disclosure is directed to a system and method for directly sampling RF signals. In some implementations, an RF reader includes a clock generator and an Analog-to-Digital Converter (ADC). The clock generator is configured to generate a sample clock signal based, at least in part, on an input signal associated with transmitting RF signals. The ADC is configured to directly sample RF signals in a receive path of the reader using the sample clock signal to generate a digital signal. Mixing of the RF signal and the sample clock, through the sampling process in the ADC, reduces phase noise associated with the transmission signal in the receive path.

Abstract: A method for use in a RFID reader, the method comprising providing an output signal from an amplifier of a transmitter, attenuating the output signal via a step attenuator, detecting and comparing the attenuated output signal to a reference value, and adjusting power to the amplifier until the attenuated output signal is substantially equal to the reference value. The attenuated output signal drives a local oscillator signal of a receiver thereby canceling noise generated by the transmitter in the receiver.

Abstract: An RFID circuit comprises an RF carrier signal source, a hybrid coupled to the RF carrier signal source operable to generate an in-phase and a quadrature phase component of the RF carrier signal, a switch coupled to the hybrid operable to pass one of the in-phase and quadrature phase components of the RF carrier signal to its output, and a mixer coupled to the output of the switch operable to multiply one of the in-phase and quadrature phase component of the carrier signal and a received modulated carrier signal and generate a baseband signal.

Abstract: The present disclosure is directed to a system and method for sampling intermediate radio frequencies. In some implementations, a method for RF communication includes receiving an analog Radio Frequency (RF) signal. The analog RF signal is downconverted to an analog signal centered at an Intermediate Frequency (IF). The analog IF signal is converted to a digital signal centered at an IF. The digital IF signal is downconverted to a digital baseband signal.

Abstract: The present disclosure is directed to a system and method for passively transferring Radio Frequency (RF) signals. In some implementations, a method for passively transferring RF signals to an interior region of a group of containers includes wirelessly receiving an RF signal incident a first portion of a container. The first portion is located at least proximate a periphery of the group of containers. The incident RF signal is passively transferred, through a wired connection, from the first portion of the container to a second portion of a container. The second portion is located at least proximate an interior portion of the group of containers. The RF signal wirelessly re-transmitted in the interior region of the group of containers.

Abstract: The present disclosure includes a system and method for reducing leakage noise in directly sampled radio frequency signals. In some implementations, a Radio Frequency IDentification (RFID) reader includes an antenna, an Analog-to-Digital Converter (ADC), a synthesizer module, and a Carrier Noise Reduction (CNR) module. The antenna is configured to receive Radio Frequency (RF) signals and pass the RF signals to a receive path. The ADC is configured to directly sample RF signals in the receive path in accordance with a clock signal and generate a digital signal. The synthesizer module is configured to generate the clock signal and a signal used to upconvert a transmitter signal. The clock signal and the upconversion signal are phase locked. The CNR module is configured to reduce leakage noise in the receive path.

Abstract: The present disclosure is directed to a system and method for backscattering different radio frequency protocols. In some implementations, a radio Frequency (RF) tag includes an antenna and a storage module. The antenna is configured to receive an RF signal from any of a plurality of readers. Each reader is associated with a different protocol having different time durations. The storage module is coupled to the antenna and configured to store energy associated with the RF signal. In addition, the storage module substantially maintains a voltage in the tag during any of the different time durations independent of an internal power supply.