Abstract: Antennas (50) for RFID tags are made to exhibit circular polarization to give the tag an omnidirectional characteristic. The antennas are crossed dipoles (52,54) with respective feed points (56,58). The signal source (60) is coupled to a splitter (62) having output leads (64) directly coupled to the feed point (56) of dipole (52). The other output leads (66) from splitter (62) are coupled to a delay line (68) with the delayed output coupled to a feed point (58) of dipole (54).

Abstract: A method of providing a defense against a shaped charge. An outer and an inner armor layer are provided with a medial space between these outer and inner armor layers. One or more defensive shaped charges are positioned in the medial space. If the outer armor layer is attacked by ordnance having an offensive shaped charge, one or more of the defensive shaped charges positioned in the medial space is detonated so as to degrade the effectiveness of the offensive shaped charge and prevent penetration of the inner armor layer.

Abstract: A microradio (10) is provided with a hysteretic switch (16) to permit an optimum range increasing charging cycle, with the charging cycle being long relative to the transmit cycle. Secondly, an ensemble of microradios permits an n2 power enhancement to increase range with coherent operation. Various multi-frequency techniques are used both for parasitic powering and to isolate powering and transmit cycle. Applications for microradios and specifically for ensembles of microradios include authentication, tracking, fluid flowing sensing, identification, terrain surveillance including crop health sensing and detection of improvised explosive devices, biohazard and containment breach detection, and biomedical applications including the use of microradios attached to molecular tags to destroy tagged cells when the microradios are activated. Microradio deployment includes the uses of paints or other coatings containing microradios, greases and aerosols.

Abstract: A method for fabrication of a field effect transistor gate, with or without field plates, includes the steps of defining a relatively thin Schottky metal layer by a lithography/metal liftoff or metal deposition/etch process on a semiconductor surface. This is followed by depositing a dielectric passivation layer over the entire wafer and defining a second lithographic pattern coincident with or slightly inset from the boundaries of the previously defined metal gate layer. This is followed by etching the dielectric using dry or wet etching techniques and stripping the resist, followed by exposing and developing a third resist pattern to define the thicker gate metal layers required for electrical conductivity and also for the field plate if one is utilized. The final step is depositing gate and/or field plate metal, resulting in a gate electrode and an integral field plate.

Abstract: A universal on-board system is provided for automatic fault detection and on-the-spot repair instructions that includes a module adapted to be coupled to a wide variety of platforms and Line Replaceable Units.

Abstract: The systems and methods described herein allow a user to communicate using a ground sensor network that is capable of both line-of-sight (LOS) and non-line-of-sight (NLOS) communication. In particular, the systems and methods herein described transmit and receive ultraviolet radiation having a wavelength within the solar blind region from a plurality of sensing nodes arranged both in a LOS network, which communicates via LOS communication, and in a NLOS network, which communicates via NLOS communication. The ultraviolet radiation is then transmitted from the plurality of sensing nodes to a remote receiver, via LOS communication.

Abstract: A Radio Frequency Identification (RFID) tag using multiple microradios and inkjet printing techniques together with a method and system for manufacturing and applying the tag to an end item are disclosed.

Abstract: A projector of multiple skewed light planes or sheets is located adjacent a vehicle to be protected and detectors are arranged to detect the penetration of the light sheets by an incoming object, with the time intervals between the piercing of the planes defining the path of the incoming object and its expected impact time. An array of bullet-firing barrels is arranged to project bullets in an iron curtain under control of a fire control module that fires a round in a barrel above the projected flight path such that the round impacts the nose of the object and disables it. It is thus the piercing of the skewed light sheets that provides information as to the impact point of the object as well as its time of arrival so that a round can be fired to intercept the object as it arrives at the iron curtain.

Abstract: Structures and techniques are disclosed that enable efficient generation of terahertz (THz) radiation capable of surpassing the fundamental quantum limit, as defined by the Manley-Rowe relations. In one particular embodiment, a difference frequency mixing (DFM) crystal stage receives pump radiation and signal radiation, and generates THz radiation. Leftover signal radiation from the DFM stage is then used to pump an optical parametric oscillator (OPO) stage, which is used to generate another mixing signal and more THz radiation. The output signal and the residual pump from the OPO stage can then be used in a subsequent DFM process to generate even more terahertz radiation, and further drives a subsequent OPO stage. Such cascaded OPO, DFM, OPO staging can be repeated to maximize total amount of THz output power.

Abstract: A method for fabricating ultra-short T-gates on heterojunction field effect transistors (HFETs) comprising the steps of (a) providing a coating of three layers of resists, with polymethylmethacrylate (PMMA) with high molecular weight on the bottom, polydimethylglutarimide (PMGI) in the middle, and PMMA with low molecular weight on the top; (b) in a first exposure, exposing and developing the layers with a dose of a developer that is high enough to allow the developer to break the top PMMA but low to avoid contributing significantly to the overall dose received in the bottom PMMA layer; and (c) in a second exposure, using an exposure and developing process to define 0.03-0.05 um openings in the bottom PMMA layer.

Abstract: Commercial aircraft are protected from attack by infrared seeking guided missiles through the utilization of a ground-based directed infrared countermeasure system in which the deployment of an IR guided missile is detected off-aircraft and more particularly on the ground. An infrared laser beam is projected towards the detected missile such that the projected laser infrared radiation impinges upon the missile from the rear. The off-axis infrared radiation illuminates the IR transmissive dome at the head of the missile where it is internally reflected back towards the IR detector carried by the missile through the total internal reflection characteristics of the dome. The domes of these missiles are typically made of a high index of refraction IR transmissive materials such that the material is prone to total internal reflection. The infrared laser generated radiation is a modulated so as to interfere with the guidance system of the missile causing it to execute a turn and plunge to the ground.

Abstract: A multi-port junction is fed with a frequency-stepped source and has one of its ports connected to an antenna that can serve either as a transmit-and-receive antenna or as a receive antenna only, with the outputs of the multi-port junction being used to estimate a complex reflection coefficient for each frequency of interest. The subject system requires no IF stages, down-conversion mixers or oscillators, and therefore may be provided adjacent each antenna at low cost. An embodiment involving co-located separate transmit and receive antennas is used to minimize the power requirements for the multi-port junction, whereas in a third embodiment, an array of transmit/receive antennas is used, fed by the same RF source but in which digitally-controlled phase shifters are used for beam-forming purposes.

Abstract: In a method for removing moisture from an optical system at high altitude, the improvement comprises using the difference in flow resistance between the desiccant path and the optical cavity path to enable airflow through the desiccant unit and not through the optical path.

Abstract: A number of identical non-uniformly distributed ultra-wideband power amplifier string building blocks are coupled together to form an ultra-wide bandwidth high-power amplifier. The non-uniform distribution results in an amplifier utilizing modular string building blocks that have input and output impedances with only real values. This permits the strings to be replicated and connected together with simple impedance matching. The internal impedance matching associated with the non-linear distribution also absorbs parasitic capacitance to permit the ultra-broadband operation. In one embodiment identical transistors are used for each cell so that the strings may be identically replicated. This permits modular re-use without reconfiguration. In one embodiment a non-uniform distributed power amplifier built using the subject building blocks provides an ultra-wideband multi-octave device suitable for electronic warfare and communications applications, especially to replace traveling wave tubes.

Abstract: A computationless system is provided for determining the direction of and distance to a target, involving bathing an area surrounding an area to be protected with a polyspectral series of narrow fan beams of different colors from at least two spaced-apart projectors. The differently colored beams go out at different angles, thus to color-code map the area surrounding the protected space where beams of different colors cross to form color-coded cells. Light reflected back to the area to be protected from a threat has a color code corresponding to the colors associated with beams that cross at the threat, thus to identify by the reflected colors where in space the threat is located.

Abstract: A method for mounting multiple small RFID chips onto larger antenna. The chips are mechanically aligned with an interdigitated gap at the feed point of the antenna by electrostatic or magnetic techniques. In an alternate embodiment RF field coupling between the chips and the antenna is employed.

Abstract: In the subject three-axis pointing system, the elevation and tip mirror axes are permanently mounted with their rotation axes orthogonal to each other to eliminate gimbal lock over the hemisphere, to avoid high accelerations as the zenith or nadir pointing directions are approached, and to provide optimal two-axis beam pointing control.

Abstract: A terahertz imaging system and method of use including a compact Yb-doped fiber laser-pumped ZGP crystal as a THz source and an uncooled microbolometer array as a detector. According to the present invention, semiconductor lasers are also drive current modulated to produce desired laser pulsewidth, repetition rate and wavelengths needed for DFG THz generation in various non-linear crystals. The fiber-coupled semiconductor lasers provide at least two wavelengths that will produce THz radiation by DFG in non-linear converter. These two wavelengths are combined and amplified in a single Yb fiber amplifier chain. Yb amplifier is staged in continually increasing core diameters to provide significant signal amplification while suppressing deleterious non-linear effects.

Abstract: A method for detonating a munition comprising the steps of providing a plurality of micro-detonators and microprocessors in said munition and initiating said micro-detonators in a predetermined sequence by means of said microprocessor. Depending on the specific predetermined sequence which is selected, one of a variety of explosive modes may be achieved.

Abstract: An antenna comprising a crossed pair of center-fed end-loaded bent-dipole radiators which are structurally embedded into a properly loaded cavity. Broadband, dual independent polarized, and hemisphere field-of-view coverage with low RCS characteristics is provided with this antenna.