Abstract: An aperture coupled microstrip patch antenna coupling circuit. Electromagnetic energy propagating along a stripline feedline is coupled through one of the ground plane surfaces through a tuned aperture to an adjacent microstrip feedline device, which may be a microstrip patch antenna. Undesirable propagation modes are suppressed by enclosing the aperture-coupled slot in a non-resonant cavity. Impedance matching is accomplished with an impedance matching section.

Abstract: An apparatus for measuring volatile organic compounds in a gas includes a sensor chamber having a housing with a gas inlet, a gas outlet, and a gas flow path from the gas inlet to the gas outlet, a set of baffles within the housing and positioned in the gas flow path, and a set of sensors within the housing and positioned in the gas flow path. Each sensor has an electrically conductive polymer whose electrical properties are dependent upon the presence of specific volatile organic compounds in the gas flow. Desirably, the set of baffles and the set of sensors are cooperatively positioned such that the time for gas to flow from the gas inlet to each of the sensors is substantially the same. The apparatus further includes a pump that removes the gas from the gas outlet of the housing, and an electronic circuit that measures the electrical properties of each of the sensors.

Abstract: A system (100) for determining particle contamination on optical surfaces (112, 114, 116) includes a detector array (118) and a non-coherent light source (110) that illuminates the detector array with non-coherent light reflected or refracted by the optical surfaces. Processing equipment (134) identifies shadows (302, 402, 502) on the detector array which are indicative of particle contamination of the optical surfaces. A light source controller (130) moves the non-coherent light source resulting in movement of the shadows on the detector array. The processing equipment distinguishes shadows caused by particle contamination on a first of the optical surfaces (112) from shadows caused by particle contamination on the other optical surfaces (114, 116) based on the movement of the shadows. The system also includes a particle contamination level analyzer (128) to estimate a particle contamination level for each optical surface from contrast levels of the shadows identified for each optical surface.

Abstract: An apparatus and method for controlling trajectory of an object (47) to a first predetermined position. The apparatus has an input layer (22) having nodes (22a-22f) for receiving input data indicative of the first predetermined position. First weighted connections (28) are connected to the nodes of the input layer (22). Each of the first weighted connections (28) have a coefficient for weighting the input data. An output layer (26) having nodes (26a-26e) connected to the first weighted connections (28) determines trajectory data based upon the first weighted input data. The trajectory of the object is controlled based upon the determined trajectory data.

Abstract: A system (16) for tracking a missile (22) in flight, the missile (22) having an optical beacon generator (32) that outputs a modulated signal (26) having a predetermined frequency, including an optical system (50, 52, 54) for transmitting image data along an optical path (68) onto an array of detectors (55), such that each detector in the array (55) receives substantially simultaneously the image data from the optical system (50, 52, 54). The system (16) further includes means for processing (46) the image data transmitted onto the array of detectors (55) in order to locate the optical beacon (32).

Abstract: A system and method for processing the output of a fiber-optic gyroscope. The inventive circuit (10) includes a photodetector (24) for detecting electromagnetic energy received from the fiber-optic gyroscope (18,20) and providing an analog input signal in response thereto. An analog-to-digital converter (42) is provided for processing the analog input signal and providing a digital signal in response thereto. A source (30) is provided for injecting a dither signal between the photodetector (24) and the analog-to-digital converter (42). In the illustrative embodiment, the source (30) supplies a triangle wave signal. The output of the photodetector (24) is supplied to the summing input of a differential amplifier (29) and the output of the source (30) supplies the differencing input to the differential amplifier (29). The output of the analog-to-digital converter (42) is provided to a digital signal processor (44) as per usual practice.

Abstract: A synchronous counter, the inventive counter is synchronized to a clock, e.g., a master clock of an FPGA, and includes a first counter that increments in response to the master clock, a resynchronizer that receives counter bits from the first counter and, when appropriate, generates an increment signal, and a second counter, clocked by the master clock, that increments in response to the increment signal. In a preferred embodiment, the resynchronizer is an n bit AND gate (where the first counter is an n-bit counter) that ANDs at least selected ones of the counter bits and a latch, e.g., a flip-flop, that latches the output of the AND gate. Thus, small counter chains are linked together using flip-flops clocked at the master clock rate, i.e., the same rate as the counter chains, to form a counter chain of any length that will function at the master clock rate.

Abstract: A passive Q switch. The inventive Q switch includes a first wedge of material adapted to absorb electromagnetic energy. The first wedge has a first thickness on a first end thereof and a second thickness on a second end thereof diametrically opposite the first end. The first wedge has a first surface connecting the first and second ends and a second surface connected the first and second ends. The second surface is slanted relative to the first surface. A second wedge of material is included in the inventive passive Q switch. As per the first wedge, the second wedge has a first thickness on a first end thereof and a second thickness on a second end thereof diametrically opposite the first end. The second wedge has a first surface connecting the first and second ends and a second surface connecting the first and second ends. The second surface is slanted relative to the first surface.

Abstract: A display device for a display wavelength range includes an image source, a relay group made of optical elements transparent to the display wavelength range, and a reflective combiner in facing relation to the relay group. The relay group includes a glass optical wedge, a glass lens, and a group of plastic lenses including a diffractive optical element. The group of plastic lenses is positioned between the glass optical wedge and the glass lens. The relay group has the optical wedge having a front face in facing relation to the image source, and a back face; an aspheric lens module having a front face in facing relation to the back face of the optical wedge, and a back face; and an aspheric lens having a front face in facing relation to the back face of the aspheric lens module, a back face, and an optical axis. The aspheric lens module is tilted and decentered with respect to the optical axis of the aspheric lens.

Abstract: A system (30) for adjusting the orientation of a spacecraft adapted for use with a satellite (10). The system (30) includes a first control circuit (32, 38, 40) for canceling any momentum of the spacecraft via a counter-rotating spacecraft bus (16, 18). A second controller (32, 42, 44, 46, 48) orients the spacecraft via the application of internal spacecraft forces. In a specific embodiment, the spacecraft bus (16, 18) serves a dual use as storage section and includes a mass (16) having a moment of inertia on the same order as the moment of inertia of the satellite (10). The satellite (10) includes a bus section (16) and a payload section (14). The mass (16) includes the bus section (16). The first control circuit (32, 38, 40) runs software to selectively spin the mass (16) to cancel the momentum of the satellite (10). The software computes an actuator control signal, via a computer (32), that drives a first actuator (38) that spins the mass (16).

Abstract: An optical system includes a nonspherical outer dome that is rotationally symmetric about a central axis, a detector system, and an optical corrector positioned in an optical path between the outer dome and the detector system. At least one light baffle is positioned in the optical path between the outer dome and the detector system and is fixed in space relative to the central axis. There are typically from one to three baffles, each affixed to either the inter surface of the outer dome or to the optical corrector. Each baffle is a frustoconical tube that is rotationally symmetric about the central axis. A set of fins may be supported on one of the baffles, with each fin extending radially outwardly from an outer surface of the baffle and parallel to the central axis. The baffles combine to reduce stray light that otherwise would enter the optical system.

Abstract: A method for exploding a high explosive material confined in a casing which includes the steps of generating a laser beam; directing the laser beam toward a location on a surface of the casing; and irradiating the surface location with the laser beam a sufficient length of time to explode the high explosive material.

Abstract: A shaping optic for diode light sheets. The Fresnel cylinder lens has a plurality of facets that channel multiple light sheet output from a diode stack having arbitrary pitch and diode bar number into a gaussian pump light deposition profile within a laser gain medium. In a specific embodiment, the lens is formed of fused silica or BK7 glass covered with broad angle anti-reflection coating, and the vertical extent of the facets is matched to the pitch spacing of the diode.

Abstract: A fin lock device (12) for a missile. The device (12) provides a mechanism for locking a missile fin (14) by grasping an edge of the fin (14) and a mechanism (32, 42) for retracting the locking mechanism (18) to release the fin (14). The fin (14) is grasped by a notch (20) therein adapted to receive the edge of the fin (14). The piston (18) is retracted by burning a pyrotechnic powder in a cavity adjacent to the piston (18) to fill the cavity with gas and create a pressure differential to force the piston (18) away from the fin.

Abstract: A missile system includes a launcher having a built-in pulse power source and an electrical connection to a missile. The pulse power source is used to send activation and firing pulses to the missile. The pulse power source utilizes a piezoelectric crystal which produces a pulse of energy when struck by a spring-loaded hammer that is released by an operator. In one version, a first piezoelectric crystal produces a first pulse to activate the system when struck by a first hammer, and a second piezoelectric crystal produces a second pulse to fire the missile when struck by a second hammer. The energy pulses are conducted from the launcher to the missile through an inductive coupling between a primary induction coil in the launcher and a facing secondary induction coil in the missile.

Abstract: A system (10) for rotating a polarization state of a beam of electromagnetic energy (22) of the present invention. The system (10) includes a first mechanism (16) for receiving the beam of electromagnetic energy (22). The beam of electromagnetic energy (22) is characterized by a first arbitrary polarization state oriented at a first angle. A second mechanism (16, 18, 20) orients the first arbitrary polarization state, via one or more waveplates (16, 18, 20), at a second angle that is different from the first angle. In a specific embodiment, the one or more waveplates (16, 18, 20) include a first quarter waveplate (16) having a principal axis (26) angled at 45° from horizontal relative to a given reference frame. A second quarter waveplate (20) is angled at −45°.

Abstract: An optically-pumped laser having a gain medium configured to provide a low loss, three-dimensional integrated optical pump cavity that substantially confines optical pump radiation within the lasing volume, which is particularly useful for efficiently pumping solid state gain media that has low pump dopant concentration. The integrated pump cavity includes a plurality of boundaries contiguous with the gain medium. An optical pump source such as a laser diode array supplies optical pump radiation that is input into the gain medium through one or more pump cavity windows with a propagation direction transverse to a laser axis defined through the gain medium. In some embodiments, an optical surface is situated opposite the window to approximately recollimate the input pump radiation. The optical pump cavity may be designed to concentrate the optical pump radiation and approximately uniformly pump the entire volume of the lasing medium.

Abstract: A compact four-way waveguide power divider (10). The inventive power divider (10) includes an input waveguide (11) that terminates at a junction with two adjacent waveguides on opposite sides of the input waveguide. On the opposite side of the junction is a conducting wall into which is built an inductive septum (20). The inductive septum (20) serves to partially match the input impedance of the structure. Second and third inductive septums (22 and 24) are also built into the output arms of the power divider (10). The purpose of the second and third septums (22 and 24) is twofold. In addition to partially matching the power divider's input impedance, the positions of the second and third septums (22 and 24) can be adjusted to equalize the power division between the output arms. Hence, the waves exiting the four output arms of the power divider have highly equalized amplitudes and phases. Further, the phases at the output ports are equalized by adjusting the lengths of the output arms.

Abstract: A glue-gun applied hot-melt radar-absorbing material (RAM) and method of use thereof is provided. The hot-melt radar-absorbing material composition comprises: (a) 70 to 85 wt % carbonyl iron powder; (b) 2 to 10 wt % of a metal deactivator; and (c) balance a thermoplastic polyurethane. The method for repair of a body comprising a radar-absorbing material, comprises: (a) formulating the hot-melt radar-absorbing material of the present invention; (b) forming the hot-melt radar-absorbing material into a shape; (c) applying the hot-melt radar-absorbing material in a molten state onto the body; and (d) allowing the hot-melt radar-absorbing material to cool to room temperature. The shape of the hot-melt RAM is advantageously a “glue stick”, which is configured to go into a glue gun. The repair operator loads the glue stick into the glue gun and pulls the trigger. The glue gun heats the glue stick, and the molten material is applied to the area to be repaired.

Abstract: An optical system has an outer dome and a detector system with an optical train and a sensor disposed to receive an optical ray passing sequentially through the outer dome and the optical train. The optical train includes a solid catadioptric imaging lens which is symmetric about a lens axis. The solid catadioptric imaging lens has a bore therethrough coincident with the lens axis, to prevent stray light from reaching the sensor. The bore is desirably filled with an opaque material or has a ground glass wall.