Abstract: A method for large volume holographic imaging is provided that may include determining projection operators within sub-volumes of a decomposed target volume, and determining a point aggregation operator for each sub-volume based on the projection operators. The method may further include receiving holographic field measurement data set captured for the target volume via the sensor array, generating a sub-volume interest value for each sub-volume by applying the holographic field measurement data set to each point aggregation operator, determining a sub-volume with a highest sub-volume interest value, and determining respective lower-tier sub-volume interest values for lower-tier sub-volumes of the sub-volume with the highest sub-volume interest value. The lower-tier sub-volumes may be defined by decomposing the sub-volume with the highest sub-volume interest value. Additionally, the method may include generating an image of the target volume based on the lower-tier sub-volume interest values.

Abstract: A holography sensor system is provided that includes an illuminator, a backscatter array, an array controller, and processing circuitry. The illuminator may be configured to output an illumination signal into a target volume. The backscatter array may comprise a plurality of backscatter elements. The array controller operably coupled to the backscatter elements, and the array controller may be configured to activate selected backscatter elements to enable the selected backscatter elements to transmit a backscatter signal in response to receipt of the illumination signal. The receiver may be configured to receive the backscatter signals from the selected backscatter elements. The processing circuitry may be configured to receive the backscatter data based on the backscatter signals from the receiver, aggregate the backscatter data with other backscatter data to form a holographic field measurement data set, and generate an image of the target volume based on the holographic field measurement data set.

Abstract: A method for large volume holographic imaging is provided that may include determining projection operators within sub-volumes of a decomposed target volume, and determining a point aggregation operator for each sub-volume based on the projection operators. The method may further include receiving holographic field measurement data set captured for the target volume via the sensor array, generating a sub-volume interest value for each sub-volume by applying the holographic field measurement data set to each point aggregation operator, determining a sub-volume with a highest sub-volume interest value, and determining respective lower-tier sub-volume interest values for lower-tier sub-volumes of the sub-volume with the highest sub-volume interest value. The lower-tier sub-volumes may be defined by decomposing the sub-volume with the highest sub-volume interest value. Additionally, the method may include generating an image of the target volume based on the lower-tier sub-volume interest values.

Abstract: A holography sensor system is provided that includes an illuminator, a backscatter array, an array controller, and processing circuitry. The illuminator may be configured to output an illumination signal into a target volume. The backscatter array may comprise a plurality of backscatter elements. The array controller operably coupled to the backscatter elements, and the array controller may be configured to activate selected backscatter elements to enable the selected backscatter elements to transmit a backscatter signal in response to receipt of the illumination signal. The receiver may be configured to receive the backscatter signals from the selected backscatter elements. The processing circuitry may be configured to receive the backscatter data based on the backscatter signals from the receiver, aggregate the backscatter data with other backscatter data to form a holographic field measurement data set, and generate an image of the target volume based on the holographic field measurement data set.

Abstract: Embodiments of the present invention relate to ultrasound (acoustic) data transmission systems, in particular data transmission over wide-band acoustic channels with frequency-dependant multi-path propagation. More specifically, embodiments of the invention involve increasing the bit rate in the acoustic channel by means of utilization of the entire ultrasound spectrum available for data transmission inside a human body.

Abstract: Embodiments of the present invention relate to ultrasound (acoustic) data transmission systems, in particular data transmission over wide-band acoustic channels with frequency-dependant multi-path propagation. More specifically, embodiments of the invention involve increasing the bit rate in the acoustic channel by means of utilization of the entire ultrasound spectrum available for data transmission inside a human body.

Abstract: Embodiments of the present invention relate to ultrasound (acoustic) data transmission systems, in particular data transmission over wide-band acoustic channels with frequency-dependant multi-path propagation. More specifically, embodiments of the invention involve increasing the bit rate in the acoustic channel by means of utilization of the entire ultrasound spectrum available for data transmission inside a human body.

Abstract: The antenna of an RFID tag is automatically tuned by controlling both the real and imaginary components impedance “seen” by the antenna. The real component (resistive) is controlled by controlling a tap of a charge pump circuit of the tag. The imaginary (reactive) component is controlled by connecting one or more reactive elements of an antenna tuning circuit to the antenna. The real component is controlled by a first digital control loop that automatically activates successive taps on a charge pump of the RFID tag which effectively controls the resistance seen by the antenna. A second digital control loop controls the connection of the various reactive components.

Abstract: Embodiments of the present invention relate to ultrasound (acoustic) data transmission systems, in particular data transmission over wide-band acoustic channels with frequency-dependant multi-path propagation. More specifically, embodiments of the invention involve increasing the bit rate in the acoustic channel by means of utilization of the entire ultrasound spectrum available for data transmission inside a human body.

Abstract: A radio frequency identification (RFID) architecture is described. RFID tags are interrogated by a reader, which may be located in a network of readers. The reader transmits symbols to the tags. Tags respond to the interrogations with symbols that each represent one or more bits of data. An RFID tag includes an antenna pad, a receiver, a state machine, and a modulator. The receiver is coupled to the antenna pad. The receiver receives a symbol from the antenna pad and outputs a received signal. The state machine is configured to determine a response symbol from the received signal and an operating state of the tag. The modulator is coupled to the antenna pad. The modulator is configured to backscatter modulate the received symbol with the response symbol. The modulator is configured to output the backscatter modulated symbol to the antenna pad.

Abstract: A method, system, and apparatus for interrogating a radio frequency identification (RFID) tag population are described. Tags are interrogated by a reader. The reader and tags engage in communication according to communications algorithms, where data symbols are exchanged between the reader and tags. Furthermore, a reader implicitly controls the operating state of every tag in the tag population by transmitting a single data symbol. Bit patterns may be collected from the tags by the reader, using a variety of interrogation techniques. In a general interrogation, the reader exchanges symbols with the tag population to interrogate the entire tag population. In a specific interrogation, a reader exchanges symbols with the tag population to target a particular tag identification number. Tags may also be placed in a superposition state by the reader, where they respond whenever a received data symbol matches the next bit of their identification number.

Abstract: Methods and apparatuses for assembling and implementing tamper indicating RFID devices are presented. An RFID device includes a substrate, an electrically conductive pattern formed on the substrate configured to operate as an antenna by separating a portion of a first device section from a second device section, and an electrical circuit mounted on the substrate that is electrically coupled to the antenna. The electrical circuit stores an identification code.

Abstract: The antenna of an RFID tag is automatically tuned by controlling both the real and imaginary components impedance “seen” by the antenna. The real component (resistive) is controlled by controlling a tap of a charge pump circuit of the tag. The imaginary (reactive) component is controlled by connecting one or more reactive elements of an antenna tuning circuit to the antenna. The real component is controlled by a first digital control loop that automatically activates successive taps on a charge pump of the RFID tag which effectively controls the resistance seen by the antenna. A second digital control loop controls the connection of the various reactive components.

Abstract: An identification (ID) tag includes a substrate having an input capable of receiving a high frequency signal. A first charge pump is coupled to the input and is configured to convert the high frequency signal to a substantially direct current (DC) voltage. A state machine is disposed on the substrate and is responsive to a data recovered by the second charge pump, where the state machine is capable of generating the control signal for the back scatter switch in response to the data. The DC voltage from the first charge pump is capable of providing a voltage supply for at least one of the data recovery circuit, the back scatter switch, and the state machine. The data recovery circuit includes a second charge pump that is capable of operating on the high frequency signal simultaneously with the first charge pump.

Abstract: Methods, systems, and apparatuses for RFID devices, such as tag test methods, are described. A tag of a strip of tags is positioned adjacent to an opening in an electrically conductive sheet, the tag having first and second orthogonally polarized antennas. A first RF test signal is transmitted through the opening to test the first antenna of the tag. The tag is positioned such that the first RF test signal has a polarization substantially the same as the first antenna and substantially orthogonal to a polarization of the second antenna. A second RF test signal is transmitted through the opening to test the second antenna of the tag. The tag is positioned such that the second RF test signal has a polarization substantially the same as the second antenna and substantially orthogonal to the polarization of the first antenna. If proper responses to both of the first and second RF test signals are received, the tag has passed the test. This test may be repeated for further tags in the strip of tags as desired.

Abstract: Methods and systems for the negotiation of a population of RFID tags with improved security is provided. In one aspect, tags are singulated without using information that directly identifies the tags in the tag population. A key is generated to identify each RFID tag of the population of RFID tags. The generated key does not include bits identifying an item with which the particular RFID tag is associated. An algorithm is operated to identify one or more tags in the population of RFIDs tags using the generated keys. In another aspect, frequency hopping and/or spread spectrum techniques are used to provide improved security while negotiating tags. In another aspect, the reader causes the tags to scroll series of bits back to the reader for each bit sent to the tags to provide improved security.

Abstract: Methods and apparatuses for assembling and implementing tamper indicating RFID devices are presented. An RFID device includes a substrate, an electrically conductive pattern formed on the substrate configured to operate as an antenna by separating a portion of a first device section from a second device section, and an electrical circuit mounted on the substrate that is electrically coupled to the antenna. The electrical circuit stores an identification code.

Abstract: A method, system, and apparatus for reading RFID tags in a stack of objects is described. For example, a pallet may hold a stack of objects, with one or more of the objects coupled to a RFID tag. A RFID reader may be used to read the tags in the stack. However, tagged objects in the middle of the stack may be difficult to read due to the RF signal loss passing through objects inside the stack. A waveguide may be used to guide radio waves to locations inside the pallet stack. For example, the waveguide can replace a slipsheet that is conventionally placed between horizontal layers of cases in the pallet stack.

Abstract: Methods, systems, and apparatuses for RFID devices, such as tag test methods, are described. A tag of a strip of tags is positioned adjacent to an opening in an electrically conductive sheet, the tag having first and second orthogonally polarized antennas. A first RF test signal is transmitted through the opening to test the first antenna of the tag. The tag is positioned such that the first RF test signal has a polarization substantially the same as the first antenna and substantially orthogonal to a polarization of the second antenna. A second RF test signal is transmitted through the opening to test the second antenna of the tag. The tag is positioned such that the second RF test signal has a polarization substantially the same as the second antenna and substantially orthogonal to the polarization of the first antenna. If proper responses to both of the first and second RF test signals are received, the tag has passed the test. This test may be repeated for further tags in the strip of tags as desired.

Abstract: Methods, systems, and apparatuses for improved tag assemblies, are described herein. In an aspect, a radio frequency identification (RFID) tag assembly includes an enclosure, a substrate, an antenna, an electrical circuit, and a plate. The substrate is coupled to an inner surface of the enclosure. The antenna is formed on a surface of the substrate. The electrical circuit is on the substrate and is electrically coupled to the antenna. The plate is attached to an outer surface of the enclosure and configured to be a ground plane for the antenna.