Abstract: A ferroelectric device that comprises a polarizing thin film of BaMF.sub.4 deposited on a substrate. Ba is barium, M is one of the metals of the group consisting of iron (FE), manganese (Mn), cobolt (Co), nickel (Ni), magnesium (Mg), and zinc (Zn). The substrate is silicon, sapphire, or gallium arsenide. A non-volatile NDRO and DRO memory cell and methods for depositing the thin film. A method of depositing bismuth titanate on a substrate are described.

Abstract: A freqency selective surface for passing electromagnetic wave energy and the selected frequency band is described. The device includes a conductive apertured substrate having apertures formed therein which are sized and arranged in a predetermined patern. The apertures each form a waveguide segment for electromagnetic energy. In one embodiment dielectric loading material is moldably formed directly into the apertures. In a bipolar arrangement, conductive patches are located on opposite sides of the dielectric coaxially with each waveguide for establishing a capacitive load in accordance with the area of the patches. Dielectric matching material on opposite surfaces of the substrate is employed to match the surface with external media for efficient electromagnetic wave propagation. Other arrangements employ notched patches and air dielectrics.

Abstract: A solid state radar transmitter for use in airborne applications has a modular design which extends into the transmitter. The transmitter is formed of a plurality of power modules the number of which is selected based on the power required for a particular application. For example, two 75 to 100 watt modules may be used for weather radar, while 30 to 60 or more modules may be used for fire control in a military fighter. A radio frequency signal from a stabilized local oscillator is distributed by a splitter to the power modules and a combiner is used to combine the output from the power modules to produce the transmitter output signal. Each power module is formed of parallel connected power amplifiers, preferably formed by GaAs FETs and a power conditioning and control unit. The power conditioning and control unit produces a DC bias across the FETs as desired to produce a particular signal.

Abstract: The present invention is a node for a network that combines a Hopfield and Tank type neuron, having a sigmoid type transfer function, with a nonmonotonic neuron, having a transfer function such as a parabolic transfer function, to produce a neural node with a deterministic chaotic response suitable for quickly and globally solving optimizatioin problems and avoiding local minima. The node can be included in a completely connected single layer network. The Hopfield neuron operates continuously while the nonmonotonic neuron operates periodically to prevent the network from getting stuck in a local optimum solution. The node can also be included in a local area architecture where local areas can be linked together in a hierarchy of nonmonotonic neurons.

Abstract: Polystatic radar system and method for operating at relatively low power for a given coverage. The illumination power density of the transmit pattern is continuously varied as a function of the range to the receiver from each point within the receive beam coverage.

Abstract: Sensor detections received over time are analyzed to find relationships therebetween. For example, radar echoes, outputs from an infrared sensor, etc., may be analyzed to find target tracks. First, gross similarities are detected by mapping, e.g., angular readings into angle bins using each of a plurality of hypothesized rates of change of angle. Those sensor detections which are found to correlate with respect to angular measurement are subjected to similar mapping into range bins using rate of change of range. The angle and range bins are compared to determine which represent target tracks. The resulting target tracks may be used to revise the parameters and repeat the same process. For example, if one of the "target" tracks detected on the first pass has an angle of 30.degree., an angle rate of 2.degree. per minute, a range of 2 kilometers and a range rate of 3 kilometers/second, this target track might be evaluated to determine whether it is a cluster of targets using angle rates varying from 1.degree.

Abstract: An apparatus and method is disclosed for making additional solder joints on a printed wiring assembly which includes a printed wiring board and components soldered previously thereto. Additional components, along with additional solder to be reflowed to form new solder joints, are placed on the assembly. A titanium shield is placed over the board to cover the already completed solder joints which are not to undergo reflow, and the assembly is passed through an oven producing both infrared and convection heating. The convection heating of the oven is set to warm the entire printed wiring assembly to a temperature which remains below the reflow temperature of the solder used to attach the preexisting components. The infrared heating of the oven is applied to the board, but is prevented from heating previously completed solder joints by the shield.

Abstract: A drain pulsing circuit for intermittently applying electric power to the drain of a solid state amplifier uses a N-channel MOSFET as the drain switch, but does not require an external bias voltage to drive the drain switch gate. The pulsing circuit generally comprises a control input circuit for generating a control pulse, and a charge pumping circuit having a capacitor that is connected to the output of the control input circuit, and first and second complementary MOSFET switches. The capacitor in the pumping circuit stores a charge during an off cycle when the control input circuit does not generate a control pulse. However, when a control pulse is generated, the first and second complementary MOSFET switches of the pumping circuit connect the gate of the N-channel drain switch MOSFET to the voltages associated with both the capacitor charge and the control pulse (which "pumps" the capacitor to a higher charge) in order to temporarily bias the N-channel drain switch MOSFET to an "on" state.

Abstract: A high power, high frequency inverter has series/parallel resonant inverter elements and employs MOS controlled thyristors (MCTs) in the switching circuit. The resonant inverter elements include a split inductor for reducing peak voltage across the switches. A fault protection circuit cause the power interruption for a short interval before restarting the circuit. High current density is achieved by means of multilayer ceramic chip capacitors and gap ferrite planar inductors.

Abstract: A source of broad-band and/or narrow band optical radiation is detected and identified by apparatus including a pair of acousto-optical tunable filters which diffract from orthogonally polarized components of the optical radiation, a diffracted ordinary polarized beam and diffracted extraordinary beam, respectively. Undiffracted polarized radiation from the two AOTFs is combined and directed to a first detector which may comprise a small array such as a quadrant array. The diffracted ordinary and extraordinary polarized beams are directed to a second detector which is preferably a single large imaging array. A signal processor uses signals from the first detector generated by the undiffracted beams to detect the presence of the source, and polarized spectral signals from the large imaging array to identify the source of the radiation . A control unit generates radio frequency signals which can be rapidly varied in frequency to control wavelength of the polarized beams diffracted by the AOTFs.

Abstract: A switchable shield which precludes transmission or receipt of radio frequency or microwave energy. The shield comprises a substrate of highly transmissive material with an active film layer disposed on the substrate. This active film layer is switchable upon heating from a high transmissivity, high resistivity mode which permits transmission or receipt of rf or microwave radiation, to a low transmissivity, low resistivity mode which precludes transmission or receipt of rf or microwave radiation through the shield.

Abstract: A unitary surface acoustic wave device for continuous quadraphase coding of a high amplitude video impulse with provisions for controlling the rise and fall times of such impulse.

Abstract: A method and apparatus which incorporates an optimization gradient algorithm for post production tuning of a microstrip microwave amplifier. The tuning technique replaces conventional time consuming manual post production tuning techniques and comprises a computerized technique which is operable to test the amplifier for its response characteristics, perturb circuit matching elements and measure the response as a result of the perturbations, and thereafter effect the required change in the circuit's tuning elements to bring the circuit response in conformance with a desired value. Perturbation is accomplished by robotic placement of dielectric chips on the matching elements while tuning is accomplished by either computer controlled laser trimming of the lengths of the tuning elements or robotic application of metallization to the tuning elements for increasing their respective lengths.

Abstract: A phased array antenna having a first plurality of phase shifters each connected to a solid state transmit module power amplifier. Equal split power combiners, each having a pair of inputs and a pair of outputs, are connected to the power amplifiers and to each other in a corporated tree hierarchal configuration. One of the pair of inputs of each of the power combiners of each higher hierarchy is connected to one of the pair of outputs of the power combiners of a lower hierarchy. A subarray is connected to the other of the pair of outputs of each of the power combiners. A subarray is connected to both outputs of the highest hierarchy. A second plurality of individual phase shifter elements are associated with the individual elements of each subarray. The first plurality of phase shifter elements adjust the illumination and phase of the signal entering each subarray. The second plurality of phase shift elements steer the beam.

Abstract: A crystal of a composition of silver, thallium, and sulfur is useful in non-linear optical devices, acousto-optical devices, piezo electric devices and other types of optical and acoustic devices. The chalcogenide glass composition of the invention displays superior transmission beyond 12 .mu.m.

Abstract: The present system performs linear transformations on input probabilities and produces outputs which indicate the likelihood of one or more events. The transformation performed is a product of linear transforms such as P.sub.o =[A.sub.j P.sub.j +B.sub.j ].multidot.[A.sub.k P.sub.k +B.sub.k ] where P.sub.j and P.sub.k are input probabilities, P.sub.o is an output event probability and A.sub.j, B.sub.j, A.sub.k and B.sub.k are transformation constants. The system includes a basic processing unit or computational unit which performs a probabilistic gate operation to convert two input probability signals into one output probability signal where the output probability is equal to the product of linear transformations of the input probabilities. By appropriate selection of transformation constants logical and probabilistic gates performing the functions of AND, NAND, OR, NOR, XOR, NOT, IMPLIES and NOT IMPLIES can be created.

Abstract: A loaded overlay coupler with capacitive stubs slows down the even mode velocity more than odd mode velocity. The quarter wavelength of the coupler cancels impedance caused by the stubs so that directivity is enhanced and impedance mismatch is minimized.

Abstract: A laser-based target discriminator system for discriminating desired objects from other objects and clutter in an image scene is disclosed. The system is operative to scan a pulsed laser beam a plurality of times across an image area, the scans covering different juxtaposed strip portions of the image area. Range differential signals are derived from the sensed information of successive laser pulsed echoes of each scan corresponding to the image elements thereof. From the range differential signalling, a binary image map of the image area is generated and converted into a second topological image map having index codes which are derived from predetermined groupings of the binary values of the first image map. Clusters of contiguous image elements are identified from the second image map based on the derived codes of the indices thereof. Desired clusters may be discriminated from the identified clusters based on measured predefined parameters thereof.

Abstract: A radio frequency coupler connector includes a housing having first and second housing portions. The first housing portion includes a first open-ended launcher operatively connected to a first connection terminal, and the second housing portion includes a second open-ended launcher operatively connected to a second connection terminal. When the first and second housing portions are assembled, the first and second open-ended launchers are overlapped and separated by a dielectric, thereby providing a non-contact connection by capacitive coupling.

Abstract: In one embodiment a diode phase shifter has a four port coupler formed of a pair of RF coupled transmission lines. The coupler has an input port on one transmission line and an output port on the other, and each transmission line has a tunable port. Serially interconnected RF isolated gateable diodes are provided, one diode is coupled to the tunable port on one transmission line and the other diode is connected to the other tunable port. The diodes approximate a microwave open circuit when reverse biased and approximate a microwave short circuit when forward biased to a conducting state. In another embodiment a diode phase shifter employing a single stripline is described.