Abstract: An optical illumination and monitoring subsystem controls the operation of a flow cytometer having a carrier fluid that flows along a channel coupled to a droplet generator, which controls a point at which droplets break off from the carrier fluid, and a droplet sorter that is operative to cause selected droplets to be sorted along one or more droplet travel paths. The subsystem is operative to illuminate a respective droplet monitoring location along each of one or more droplet travel paths with a respective beam of light, such as that sourced from a common laser. In response to backscatter reflection from a droplet passing through the respective beam of light at a respective droplet monitoring location, the amplitude of the beam of light is increased. Then the droplet is monitored for the presence of a particle therein exhibiting detectable fluorescence as a result of the increase in the amplitude of the respective beam of light.

Abstract: A signal processing operator successfully expands the dynamic range of a histogram of digital data, such as that representative of biological cell populations, including human blood cells subjected to flow cytometry processing, without introducing binning artifacts into the transformed data. The inventive data mapping scheme effectively preserves statistical probability distribution characteristics of the original data, that would otherwise be removed or lost in the course of expanding the dynamic range of a quantized histogram data set through the use of a conventional log transformation. Filtering is unnecessary, as the binning effect is countered early in the process, to preserve statistical properties of the cell populations under study.

Abstract: A physically compact (saline) solution preparation apparatus includes a solution mixing tank coupled to sources of concentrate and diluent. A concentrate transport path is configured to both homogenize and deliver concentrate to the mixing tank, while the diluent transport path is controllably purged of potential contaminates prior to supplying the diluent to the mixing tank. A mixed solution transport path recirculates and thereby homogenizes the contents of the mixing container, and actively pumps out solution that has been mixed to a prescribed conductivity-based concentration, to one or more solution on demand storage reservoirs for respective instruments. The operation of the apparatus is based upon measured conductivity of the contents of the solution mixing tank, so that there is no need to conduct precursor volumetric measurements of either diluent or concentrate.

Abstract: A periodic waveform-based wireline measurement circuit derives a voltage that is very precisely proportional to the differential voltage across a wireline pair, and uses this voltage to modulate the width of a periodic waveform, such as one derived from a ringing signal. This periodic waveform can be interfaced in an asynchronous manner with digital processing components, such as a DSP codec, to provide for automatic compensation for the resistance of the phone line.

Abstract: A junction field effect transistor (JFET) RF oscillator-detector circuit generates an RF signal for an apparatus for conducting electrical measurements of particles contained in a carrier fluid passing through an aperture in a cytometer flow cell. The JFET oscillator includes a plurality of parallel-coupled JFETs having respectively different VDS vs. IDS characteristics, that are biased to operate at square law detection regions of their respective VDS vs. IDS characteristics. One JFET operates in Class C mode, while the other operates in Class AB mode. An RF resonant circuit is electrically coupled to the JFETs and to the measurement cell, and is operative to establish the frequency of an RF field applied to the measurement cell. An RF load change detection circuit is coupled to the RF resonator circuit and is operative to detect an RF load change associated with a modification of the RF field as a result of a particle within the measurement cell aperture.

Abstract: A junction field effect transistor (JFET) RF oscillator-detector circuit generates an RF signal for an apparatus for conducting electrical measurements of particles contained in a carrier fluid passing through an aperture in a cytometer flow cell. The JFET oscillator includes a plurality of parallel-coupled JFETs having respectively different VDS vs. IDS characteristics, that are biased to operate at square law detection regions of their respective VDS vs. IDS characteristics. One JFET operates in Class C mode, while the other operates in Class AB mode. An RF resonant circuit is electrically coupled to the JFETs and to the measurement cell, and is operative to establish the frequency of an RF field applied to the measurement cell. An RF load change detection circuit is coupled to the RF resonator circuit and is operative to detect an RF load change associated with a modification of the RF field as a result of a particle within the measurement cell aperture.

Abstract: A particulate sample mixing and delivery apparatus externally sonically mixes respective samples of particulate stored in storage containers that are sequentially indexed by a carousel prior to being dispensed into an analyzer reservoir. Each container is compliant to acoustic energy emitted by a sonicator unit that is placed against an external surface of a respective container to which preferably a carrier fluid and surfactant are controllably supplied. After sonication, the container is indexed to a sample dispensing location adjacent to the analyzer reservoir. A tiltable cradle then rotates the container to rapidly dispense its mixed contents into the reservoir, and then discards the empty container.

Abstract: A flow cytometer sorting mechanism is operative to controllably sort successively generated fluid droplets in accordance with the contents of a plurality of contiguous precursor regions of the carrier fluid which are contained within a target droplet of interest and precursor regions for droplets on either side of the target droplet. This multi-region sorting window scheme is particularly useful in reducing the time required to harvest a highly purified quantity of a particular type of cell, as not only are droplets containing only desired cells sorted to a highly purified collection store, but should an undesired cell be detected within a predefined proximity of a desired cell, rather than being simply aborted, the droplet is sorted into an auxiliary enrichment container, whose contents may then be reclaimed for resorting. Since all droplets are sorted to one of a plurality of droplet reclamation containers, substantially no detected/target cells are lost.

Abstract: A differential DC/RF bridge-configured flowcell particle detector includes a flowcell and an adjustable circuit model of the flowcell, which are differentially coupled through output amplifier circuits and galvanically isolated from sources of signal degradation. The output of the difference amplifier is coupled to a DC/RF discriminator and associated downstream processing circuitry. Respective amplitude and phase outputs of the DC/RF discriminator are used to control amplitude and phase adjustment circuits of the adjustable circuit model, so as to automatically track amplitude and phase variations in the non-linear behavior of the flowcell, to mirror the characteristic impedance of the flowcell, thereby making the bridge insensitive to variations in the flowcell.

Abstract: A polarization-independent polychromatic light modulator applies one or more pairs of predetermined RF drive frequencies to an acousto-optic transducer of an acousto-optic modulator body upon which a single beam of randomly polarized or unpolarized polychromatic input light is incident. No precursor polarization separation elements are employed. For each optical wavelength to be extracted from the incident beam, two RF drive frequencies are employed. The acoustic waves launched into the acousto-optic medium by the application of the two frequencies of a given RF drive frequency pair produce respective +1 and -1 order output beam components of the selected output wavelength (as well as a zeroth order beam for that wavelength).

Abstract: A stripline cross-over architecture includes a first stripline layer extending on a first side of a dielectric layer between a first signal input port and a plurality of first signal output ports. A second stripline layer extends on a second side of the dielectric layer between a second signal input port and a plurality of second signal output ports, crossing over the first stripline layer at a plurality of cross-overs of mutual overlap therebetween. The electrical lengths of the stripline layers are defined and the cross-overs are located such that electrical distances between the cross-overs and signal combination locations cause cross-coupled signals to cancel one another, when non cross-coupled signals are combined in phase.

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: A satellite data processing aircraft icing detection and display mechanism comprises a communication link coupled with an earth-imaging satellite containing a terrestrial-directed imagery sensing system, which conveys data associated with multiple images representative of characteristics of the earth's atmosphere in a viewed terrestrial area. A digital imagery data processor is coupled to the communication link, and is operative to process the data to provide an indication of intensity and height of potential areas of aircraft icing. An icing display subsystem is coupled with the digital imagery data processor and is operative to generate a multi-pixel map image showing the geographical location, intensity and height of an identified aircraft icing layer.

Abstract: A hybrid system for stabilizing the attitude of an instrument relative to a dynamic platform includes a plurality of (roll, pitch and yaw) inertial rate sensors, whose outputs are sampled at a rate sufficient to provide real time tracking of changes in orientation of the platform, and a global positioning system (GPS) receiver, whose precision platform attitude output is updated periodically, but at a rate less than the rate of change of attitude of the platform. The inertial rate sensors provide effectively continuous motion (e.g., angular rate) data signals representative of three-dimensional changes in attitude (position derivative signals) of the platform. The inertial rate output are integrated to provide output signals representative of the dynamic orientation of the platform. Sequential outputs of the integration-processing circuitry are also coupled to a sample buffer, which is controllably read-out in accordance with the periodic updates from the GPS receiver.

Abstract: An out-of-band signaling mechanism for a T-1 multipath digital time division multiplex telecommunication system transports signaling information exclusive of in-band, robbed bit signaling. The out-of-band signaling mechanism reserves a portion of the available bandwidth of a DS0 channel for exclusive transport of signaling information as an out-of-band DS0 signaling channel, and employs the remaining portion of the available bandwidth of that same DS0 channel as a sub-rate data communication DS0 channel.

Abstract: A gain-optimized, compact helical antenna array comprises an array of tapered pitch angle helical antenna elements. By tapered pitch angle is meant that the pitch angle increases from the base end of the antenna element to the distal end, in a manner that optimizes the gain of each helical element relative to helix length for a given physical size of the winding. Each helical winding is coupled to a signal distribution network, through which the antenna's radiation pattern is controllably defined. The antenna elements have a spatially aperiodic distribution, that reduces grating lobes, by minimizing the number of antenna elements which share the same azimuth. A radial line orthogonal to the boresight axis will intercept a minimum number of helical antenna elements of the array.

Abstract: An RF power amplifier linearization architecture has a pair of matched RF amplifiers, RF signal paths through which are intercoupled with a phase and amplitude measurement and predistortion mechanism. By selectively combining the RF output of a main path RF power amplifier with the RF input signal supplied to a parallel path RF power amplifier, the predistortion control mechanism of the invention predistorts the RF input signal applied to the parallel path amplifier, so that it includes the same modulated RF carrier component as that applied to the main path amplifier, as well as a complementary version of the intermodulation component of the output of the main path amplifier. The predistortion for each amplifier is controlled such that the resulting RF output signals produced by the matched amplifier pair will have the desired RF carrier modulation component but equal amplitude and phase-reversed intermodulation components.

Abstract: To form a shallow well MOSFET, an epitaxial layer is subjected to a blanket implant of impurities, so as to form a very shallow well region that defines a PN junction with the epitaxial layer. A field oxide layer is selectively formed on a portion of the shallow well region, and a gate insulator layer is formed on the exposed portion of the shallow well region contiguous with the field insulator layer. A polycrystalline silicon spacer-gate layer is non-selectively deposited on the field insulator layer and the gate insulator layer, forming a multiple thickness implant mask. The resulting structure is subjected to one or more high energy impurity implants, to overdose and thereby convert a portion of the shallow well region to the conductivity of the epitaxial layer. This extends the PN junction up to the surface of the well region beneath the gate insulator layer, thereby defining the length of the channel between the side edge of the field oxide layer and the extended PN junction.

Abstract: An RF power amplifier linearization architecture contains main and auxiliary path RF amplifiers. A distortion-inverting circuit extracts the distortion component from the output signal of the main amplifier and combines it with a delayed sample of the RF input signal to drive an auxiliary path RF amplifier, via a predistorter. An output quadrature hybrid combines the output of the main and auxiliary path amplifiers. The cascading of the distortion-inverting circuit with the predistorter compensates for the non-linear behavior of the auxiliary path RF power amplifier thereby producing a composite signal at the output quadrature hybrid, in which RF carrier components from each amplifier combine constructively while distortion components cancel.

Abstract: A demand-based connection management satellite communication network includes a plurality of geographically distributed earth stations, each earth station having a frame relay protocol-based switch for interfacing message signals between terminal devices and modem unit. One of the earth stations is a hub station whose modem unit includes plural demodulators tuned to carrier frequencies transmitted from other, remote stations. Each remote station has at least one hub-programmable demodulator and/or a programmable modulator. When an originating station receives a request from a terminal device for connectivity with a terminal device at a destination station, it transmits a connectivity request message to the hub station. In response, the hub station checks a demodulator and/or modulator frequency assignment database for demodulator availability.