Abstract: A single-event upset immune frequency divider circuit is disclosed. The single-event upset immune frequency divider circuit includes a dual-path shift register, a dual-path multiplexor, and a summing circuit. The dual-path shift register has a clock input, one signal input pair and multiple signal output pairs. The dual-path multiplexor has multiple signal input pairs and one output pair. The signal input pairs of the dual-path multiplexor are respectively connected to the signal output pairs of the dual-input shift register. The dual-path multiplexor selects one of the signal output pairs of the dual-path shift register for feeding back into the signal input pair of the dual-path shift register. The summing circuit then sums the signal input pair of the dual-path shift register to generate an output clock signal that is a fraction of the frequency of an input clock signal at the clock input of the dual-path shift register.

Abstract: A single-event upset immune flip-flop circuit is disclosed. The single-event upset immune flip-flop circuit includes a first single-event upset immune latch and a second single-event upset immune latch. The first single-event upset immune latch has two inputs and two outputs. The second single-event upset immune latch also has two inputs and two outputs. The two inputs of the second single-event upset immune latch is connected to the two outputs of the first single-event upset immune latch. The state of the first single-event upset immune latch changes only when the signal polarities at both inputs of the first single-event upset immune latch are identical. Similarly, the state of the second single-event upset immune latch changes only when the signal polarities at both inputs of the second single-event upset immune latch are identical.

Abstract: A braking device for increasing the drag coefficient of an associated shell at a desired point while in flight is described. The device comprises: at least two braking vane means which, when released, extend substantially symmetrically into a surrounding airstream while said shell is in flight; retaining means for maintaining said at least two vane means in a retracted first position out of said airstream during an initial portion of said flight; releasing means to allow said at least two vanes to extend to a second position into said airstream at a desired point during said flight; said at least two vane means being extended by centrifugal force due to rotation of said associated shell about its axis; and, said at least two vane means further including co-operating means to ensure substantially symmetrical extension into said airstream.

Abstract: A single-event upset immune frequency divider circuit is disclosed. The single-event upset immune frequency divider circuit includes a dual-path shift register, a dual-path multiplexor, and a summing circuit. The dual-path shift register has a clock input, one signal input pair and multiple signal output pairs. The dual-path multiplexor has multiple signal input pairs and one output pair. The signal input pairs of the dual-path multiplexor are respectively connected to the signal output pairs of the dual-input shift register. The dual-path multiplexor selects one of the signal output pairs of the dual-path shift register for feeding back into the signal input pair of the dual-path shift register. The summing circuit then sums the signal input pair of the dual-path shift register to generate an output clock signal that is a fraction of the frequency of an input clock signal at the clock input of the dual-path shift register.

Abstract: A fast deployment and retrieval system permits the rapid deployment of a decoy in seconds in response to an incoming threat, thus eliminating the necessity of pre-deployment, with retrieval permitting reeling in and deployment of the decoy a number of times during a mission in response to threats, and a commensurate reduction in life cycle cost. Upon detection of an incoming threat by a warning receiver, a controller coupled to a transmission releases a brake that is utilized to control the speed of deployment, whereas upon retrieval, the transmission drives a motor for retrieval of the decoy. The system is thus reusable, fast reacting, and also minimizes range penalty considerations because the decoy is only deployed when needed. In one embodiment, the system accommodates both a towing cable and a fiber-optic signal cable in which apparatus for unwinding of the cables is mechanically ganged together so that the cables pay out at the same rate.

Abstract: A coherent radar detection system (2) comprises a radar signal transmitter (4) and a correlation receiver (6). The transmitter (4) comprises a waveform generator which generates a signal at an intermediate frequency. The signal is divided into two divided signals by a coupler, and then the divided signals are mixed together in a mixer to generate an output signal which has a wider bandwidth than the intermediate frequency. The bandwidth can be increased further by repeating the coupler/mixer stage. The system generates very wide bandwidth signals coherently, allowing coherent processing in high resolution range gates.

Abstract: Radiation synthesizer systems provide efficient wideband operation with loop antenna elements which are small relative to operating wavelength. Energy dissipation is substantially reduced by cycling energy back and forth between a high-Q radiator and a storage capacitance under control of a switching circuit. Systems using multi-segment loop antennas match input impedance to switching circuit parameters. Use of such antennas in crossed-loop configurations excited in quadrature and supported on a wearable garment provide body-borne antennas with isotropic type coverage. With light-weight flexible construction, a wearable radiating system can avoid any need for visually identifiable features and provide effective antenna pattern coverage regardless of the wearer's body orientation, whether standing, prone or otherwise.

Abstract: An apparatus for providing mechanical support to a column grid array package is disclosed. The column grid array package uses solder columns to provide electrical connections between a ceramic substrate and a printed circuit board. The ceramic substrate has two sides, with an integrated circuit chip mounted on one side and many input/output pads mounted on the other side. Solder columns are attached between the input/output pads and the printed circuit board. A corner post is located at each corner of the column grid array package to secure the position of the ceramic substrate in relation to the printed circuit board.

Abstract: Techniques for minimizing stress induced by temperature changes in an integrated circuit (e.g., focal plane array or processor) or other such assemblies that include materials having mismatched coefficients of thermal expansion/contraction are disclosed. A thermal interface including a flexible comb-like pattern enables compensation for mismatched coefficients thereby reducing thermal-related stress.

Abstract: An inexpensive, small, low-power consumption, wide-band, high resolution spectrum analyzer is provided as a listening device for throw-away applications such as surveillance that involve deployment of large numbers of battery-powered spectrum analyzer modules to detect a signal source such as two-way radio traffic. Power requirements are minimized by the utilization of only one chirp generator to elongate battery life while providing a high resolution result. In order to minimize power drain the spectrum analyzer includes a single compound-chirp Fourier Transform generator. The compound chirp generator is used in one embodiment with a surface acoustic wave, SAW, dispersive delay line in conjunction with a surface electromagnetic wave, SEW dispensive delay line.

Abstract: A fault detection system for detecting an unwanted electrical path between a reference potential and at least one of: a) a floating power source, b) a first power conductor coupled to a first terminal of the power source, and c) a second power conductor coupled to a second terminal of the power source. The system comprises an impedance network electrically coupled to the first and second power conductors and having an output terminal for providing a first voltage signal with respect to the reference potential, and an amplifier circuit responsive to the first voltage signal and to a reference voltage for generating an amplified signal indicative of the existence of the unwanted electrical path when the difference between the first voltage signal and the reference voltage exceeds a predetermined value.

Abstract: A method of producing an aircraft assembly tool for supporting an aircraft component comprising calculating a plurality of predetermined positions and corresponding orientations in space at which the aircraft is to be supported, designing a fixture frame at predetermined locations of the frame associated with the predetermined positions, constructing the fixture frame, providing pick-up devices with receiving elements, securing the pick-up devices to the fixture frame, and adjusting each receiving element.

Abstract: Recovery of a towed body, in one embodiment in the form of a decoy which is initially stowed in a receptacle or canister and which is allowed to pay out behind an aircraft on a towing cable wrapped around a spindle, is accomplished by snaring or lassoing a portion of the towing cable and by dragging it to a further spindle which is driven so as to cause the lasso and a portion of the towing cable to wind up around the driven spindle. When a sufficient amount of the cable is wound around the driven spindle, the cable end secured to the canister is severed to allow all of the rest of the towing cable to be wound up. In one embodiment, a telescoping saddle or docking cradle is provided which extends from the canister to receive the retracted towed body so that it may be secured to the moving vehicle from whence it can be recovered, refurbished, and redeployed.

Abstract: The determination of the geographical location of a signal emitter by the coherent, time integrated measurement of received signal wavefront phase differences through a synthetic aperture and the reconstruction of the wavefront of the received signal. The location of an emitter is determined by coherently measuring the phase gradient of an emitted signal at measurement points across a measurement aperture. Each measured phase gradient is integrated to determine a vector having a direction from the measurement point to the signal emitter and an amplitude proportional to the received signal. A figure of merit is determined for each possible location of the signal emitter by integrating each vector with respect to a propagation path between the measurement point of the vector and the possible location of the signal emitter, and the location of the signal emitter is determined as the possible location of the signal emitter having the highest figure of merit.

Abstract: The method of constructing a skin for a member 30 of a body such as an aircraft comprises providing from a multi-axial fabric first and second pieces A, A1 shaped to correspond respectively to the shape of the member 30 to be covered by the skin and to the shape of a similar member 32 on the opposite side of the body, and inverting one of the pieces and placing it on the other. The method may include providing third and fourth pieces B, B1 from multi-axial fabric shaped to correspond respectively to the shape of the member 30 to be covered by the skin and to the shape of the similar member 32 on the opposite side of the body and inverting one of the third and fourth pieces B, B1 and placing it on the other to form a skin for the similar member.

Abstract: A computer device includes an interface board, a plurality of peripheral component interface (PCI) busses on the interface board, and a plurality of device card connectors carried by the interface board. The plurality of device card connectors include at least one first device card connector coupled to first and second PCI busses synchronous with one another, and at least one second device card connector coupled to the second PCI bus and to a third PCI bus asynchronous with the second PCI bus. The PCI busses are thus connected so that the PCI busses may be added in groups according to the number of device card connectors supported by the interface board, and not by the loading constraints of the PCI busses themselves. By defining both synchronous and asynchronous device card connectors, device cards requiring either synchronous or asynchronous communications may be utilized by the computer device.

Abstract: A clock splitter circuit provides a radiation hardened pair of adjustably non-overlapping complementary clocks. The circuit includes a pair of clock inverter legs. Each clock inverter leg can include an and-or-inverter (AOI) circuit having a first input coupled to an overlap_en signal, a second input coupled to an inverted overlap_en signal, a third input coupled to an inverted first clock input signal, and a fourth input coupled to an second clock input signal that is substantially 180 degrees out of phase with the first clock input signal. Each clock inverter leg can further include an asymmetric variable delay (AVD) circuit having an input coupled to an output of the first AOI circuit and an input coupled to a waitr_signal that can be used to delay and adjust breadth of non-overlap. Each leg can further include a tri-state inverter circuit having a first input coupled to an output of the AVD circuit, and a second input coupled to the inverted first clock input signal.

Abstract: A system is provided for increasing the brightness and color saturation of a liquid crystal display to permit direct sunlight viewing which includes the utilization of an array of diffractive color separation microlenses which serve both to spatially separate incoming white light into red, green and blue bands which do not overlap and to focus the bands onto a subpixel matrix such that each of the sub-pixels is illuminated with only one color. The diffractive color separation is made possible through the utilization of the iterative genetic algorithm which specifies the stepped surface of the lens that provide for exceptionally fine color separation. In one embodiment the genetic algorithm is applied iteratively to define the optimal stepped surfaces which are utilized to focus the various colors at different positions at the focal plane of the lens. The subject system improves the overall transmission efficiency of 5% for a standard liquid crystal display to in excess of 30% overall efficiency.

Abstract: A radiation-susceptible integrated circuit comprises radiation sensor, a differential amplifier and circuit disabler. The radiation sensor includes two devices that have a different tolerance to ionizing radiation. When exposed to a total dose of ionizing radiation that exceeds the radiation tolerance of one of the devices but not the other, only the more radiation-susceptible device will exhibit an increase in leakage current. The differential amplifier is operable to generate an output signal having a value that is indicative of a difference or offset that exists between the output of the two devices. The output signal from the differential amplifier is received by the circuit disabler, which is activated, or not, as a function of the value of the output signal.

Abstract: An apparatus for collecting and detecting chemicals contained in a fluid includes a sorbent element, at least one chemical sensor, a first pump for pumping fluid through the sorbent element and a second pump for pumping fluid to the chemical sensor. The sorbent element contains a sorbent material and a heating element. The first pump pumps fluid into the sorbent element thereby collecting the chemicals on the sorbent material. The heating element provides heat to the sorbent element to desorb the chemicals from the sorbent material. The chemicals desorbed from the sorbent material are then pumped out of the sorbent element and to the chemical sensor. The sorbent material may have a cavity therein with the heating element located in that cavity. Alternatively, the heating element may be interposed between the enclosure and the sorbent material.