Abstract: A biosensor system includes a first optical waveguide optically coupled to a light source; a first ring or disk resonator optically coupled to the first optical waveguide; and a monitoring system that signals the presence of a biological material based on a detected change in one or more transfer characteristics of the first ring or disk resonator.

Abstract: Systems and method for manipulating optical pulses to implement an optical switch and for pulse shaping (e.g., pulse compression and/or compression) are disclosed. In one embodiment, the system comprises an optical switch apparatus that includes a plurality of resonators optically coupled to a waveguide, two output waveguides, an input light source, a control light source. The system selects some of the input signals emitted from the input light course using control signals emitted from the control light source to route to one of the output waveguides. In another embodiment, the system includes a waveguide optically coupled to a plurality of resonators, input light source, optional resonator modules that can change the refractive index of the resonators, and an optional amplifier. This system can change the shape of the pulses by changing a number of parameters, such as the incoming pulse amplitude and/or the refractive index of the resonators.

Abstract: A system and method for identifying objects within a monitored environment includes a plurality of tag signal readers contained within the monitored environment and serially connected along a single connection line as a coaxial cable for receiving tag signals from at least one tag contained within the monitored environment. The tagged signals received by tag signal readers are timed and associated with a particular tag signal reader, such as by the use of multiplexing techniques. A location processor is connected to the single connection line and determines which tag signals are first-to-arrive signals and conduct differentiation of the first-to-arrive signals to locate a tag.

Abstract: A location system includes a plurality of signal readers for receiving signals from a wireless transmitter to be located. The signals include a wideband, spread spectrum signal and a timing marker appended a predetermined time in front of the wideband, spread spectrum signal for indicating the presence of the wideband, spread spectrum signal. A location processor is operatively coupled to the signal readers for detecting the timing markers of signals and responsive to a detection of a timing marker, correlating a signal as a first-to-arrive signal and conducting differentiation of first-to-arrive signals to locate a wireless transmitter.

Abstract: A system of the present invention is operative for locating a wireless mobile device in communication with a wireless local area network (WLAN) that includes a plurality of cells defining a wireless local area network each having an access point base station. The access point base stations communicate with wireless mobile devices using wireless communication signals as typically spread spectrum communication signals. A processor is operatively connected to each of the access point base stations and operative to process communication signals transmitted from a mobile device and determine which signals are first-to-arrive signals based on a common timing signal and conduct differentiation of the first-to-arrive signals to locate the mobile device.

Abstract: A system and method for identifying objects within a monitored environment includes a plurality of tag signal readers contained within the monitored environment and serially connected along a single connection line as a coaxial cable for receiving tag signals from at least one tag contained within the monitored environment. The tagged signals received by tag signal readers are timed and associated with a particular tag signal reader, such as by the use of multiplexing techniques. A location processor is connected to the single connection line and determines which tag signals are first-to-arrive signals and conduct differentiation of the first-to-arrive signals to locate a tag.

Abstract: A wireless local area network and location system for locating objects within a monitored environment are disclosed. A plurality of access point stations receive and transmit communication signals within a wireless local area network. A processor is operatively connected to each of the access point stations and operative for processing communication signals received from the mobile station and, in one embodiment, determining which communication signals are first-to-arrive signals and conducting differentiation of the first-to-arrive signals to locate a mobile station. Delayed versions of at least one interference signal are weighted and the amplitude and phase controlled with weighted functions W1, W2. . . Wn. The resultant weighted replicas are summed to determine an approximation of disbursed interference for cancelling interference. The location system can include a tag transmitter and spaced monitoring receivers and processor.

Abstract: A magnetic field-based tagged object information storage and retrieval system employs a spread spectrum modulated magnetic field for identifying each of a plurality of tagged objects to which spread spectrum modulation magnetic field transponders are attached. When interrogated by a tag reader, transponders embedded in plural tags generate spread spectrum modulated magnetic fields that are correlated with a reference spreading sequence in a tag reader signal processor to both detect and identify each responding tag.

Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration transmissions from object-attached tags, to geolocate objects within a monitored environment. An object location processor is coupled to distributed tag transmission readers over signal transport paths having different transport delays, and carries out time-of-arrival differentiation of first-to-arrive transmissions from a tag to determine where its object is located. Geolocation errors associated with variations in parameters of the signal transport paths are effectively removed by installing one or more ‘reference’ tags, whose geolocations are precisely known. Using a background calibration routine that is exercised at a relatively low cycle rate, emissions from the reference tags are processed and coupled to the geolocation processor. The calculated geolocations of the reference tags are compared with their actual locations.

Abstract: A reader geometry visualization tool for a geo-location system technician's personal computer is operative to display a map of an asset management environment. The technician interactively places and manipulates a distribution of tag transmission readers and any potential impairments to RF transmissions on the map. The locations of the readers (and any impairments) are coupled as input parameters to a mathematical model of a tag-based geo-location system. The performance of the map-parameterized geo-location system model is then computed as a geometric dilution of precision (gdop) value for the intended object coverage area. The computed (gdop) performance is visually characterized on the displayed map, as by way of different colors to indicate how accurately the proposed reader geometry will enable the system to locate objects anywhere in the coverage area.

Abstract: To accommodate the large frequency uncertainty associated with low cost spread spectrum systems, a matched filter architecture is subdivided into cascaded sub-symbol filter segments, the number of which is selected to prevent loss of unacceptable signal energy over the received signal frequency uncertainty. The sub-symbol filter segments are processed in plural phase rotation-signal combiner stages, outputs of which are associated with multiple frequency bins. A respective phase rotation-signal combiner stage multiplies sub-symbol filter segments by respectively offset phase rotation vectors, associated with the plural frequency bins. The sub-symbol phase vector products of each stage are summed to produce plural frequency bin outputs.

Abstract: An object tracking system for locating radio-tagged objects has a plurality tag transmission readers that detect tag transmissions, and generate time-of-arrival output signals representative of the time-of-arrival of first-to-arrive tag transmissions on the basis of clock signals generated by local clock generators at the tag reader sites. The tag reader sites may transmit time-of-arrival signals to an object location processor by way of a wireless local area network. Measurements made on transmissions from a fixed position reference tag are used to update a reader clock offset database employed by the processor to maintain the reader clocks effectively time aligned.

Abstract: In order to geolocate a wireless communication device (cellular phone) initiating a 911 call, a base station transceiver transmits a supervisory audio tone (SAT), which is automatically looped back by the calling cellular phone. Returned SAT signals are correlated with those transmitted to determine the range of the cellular phone. In addition, incoming signals from the cellular phone, such as the returned SAT signals, are received by a phased array antenna and subjected to angle of arrival processing to determine the direction of the cellular phone relative to the base station. Given this angle of arrival and range information the cellular phone is geolocated.

Abstract: In order to geolocate a wireless communication device (cellular phone) initiating a 911 call, a base station transceiver transmits a supervisory audio tone (SAT), which is automatically looped back by the calling cellular phone. Returned SAT signals are correlated with those transmitted to determine the range of the cellular phone. In addition, incoming signals from the cellular phone, such as the returned SAT signals, are received by a phased array antenna and subjected to angle of arrival processing to determine the direction of the cellular phone relative to the base station. Given this angle of arrival and range information the cellular phone is geolocated.

Abstract: Devices are made comprising a tin-phosphorous oxyfluoride glass, which has been exposed to light, preferably shorter in wavelength than the absorption edge of the glass, to change the refractive index change of the glass. The glasses can be used to form planar and fiber devices, including core/clad structures for guiding light.

Abstract: A magnetic field excitation and detection coil arrangement is configured to produce an electrical output signal representative of a differential combination of responses from a plurality of magnetic fields, including the field emitted from the excitation coil, a response magnetic field emitted from an object-tagged transponder interrogated by the excitation coil, and other magnetic fields from extraneous sources, such as industrial machinery. This differential combination of the responses from the detection coils will contain only the desired signal (e.g., response from an object-tagged transponder), as the other far away fields cancel, and therefore produces a net output signal level for a downstream signal (transponder output) processor.

Abstract: An object orientation-independent information storage and retrieval system ‘tags’ an object with a compact, strip-embedded transponder containing object identification information. The transponder remains unpowered until the tagged object passes through a pulsed time-varying magnetic field generated by a tag reader. In response to a transponder coil sensing this interrogation magnetic field, the transponder extracts and stores energy from the incident field, powering up the transponder and stimulating the emission of an alternating magnetic field reply burst encoded with information stored in memory. The reply burst has the same frequency as the interrogating magnetic field burst, and is emitted by the transponder coil prior to receipt of the next interrogation burst.

Abstract: A distributed radio geo-location and tracking system has a distributed subsystem architecture that distributes its processing workload over a plurality of information handling and processing subsystems. For maximum detection capability, each of a plurality of tag emission receivers is equipped with a circularly polarized, omnidirectional antenna, to provide hemispherical coverage. The receivers are coupled to a partitioned plurality of detection processors, that are coupled via distributed association processors to multiple location processors. Each detection processor demodulates and time stamps received energy correlated to known spreading codes of the tags, to associate received energy with only one tag. It transmits a message containing this information over a communication framework to an association processor.

Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration pulse `blinks` from object-attached tags, to provide a practical, continuous identification of the location of each and every object within an environment of interest, irrespective whether the object is stationary or moving. Correlation-based RF processors determine which signals received spatially diverse antennas coupled to tag transmission readers are first-to-arrive signals as transmitted from any blinking tag. An object location processor carries out time-of-arrival differentiation of first-to-arrive transmissions from any blinking tag to determine where the respective object is located within the environment.

Abstract: An asset management radio location system uses time-of-arrival differentiation for random and repetitive spread spectrum, short duration pulse `blinks` from object-attached tags, to provide a practical, continuous identification of the location of each and every object within an environment of interest, irrespective whether the object is stationary or moving. Correlation-based RF processors determine which signals received spatially diverse antennas coupled to tag transmission readers are first-to-arrive signals as transmitted from any blinking tag. An object location processor carries out time-of-arrival differentiation of first-to-arrive transmissions from any blinking tag to determine where the respective object is located within the environment.