Abstract: According to a first aspect of the present invention, there is provided a duplexer for a radio frequency antenna, comprising: a radio frequency signal transmitter port arranged for connection to a radio frequency signal transmitter; a radio frequency signal receiver port arranged for connection to a radio frequency signal receiver; a switch arranged selectively to adopt either one of: a first state which connects the transmitter port to a common input/output port of the switch arranged for connection to a radio frequency antenna; and a second state which connects the receiver port to the common input/output port; a switch control unit arranged to monitor radio frequency power at the common input/output port and to receive a transmission gate signal; wherein the switch control unit is arranged to control the switch to adopt the first state upon receipt of the transmission gate signal, and, subsequently, to control the switch to adopt the second state when the monitored radio frequency power falls below a thres

Abstract: A method of producing an assembly tool (60) for assembling an assembly (6), the method comprising: providing at least a portion of a jig frame (62); fixing support plates (65) to the jig frame (62); machining the one or more support plates (65) such that a surface of each of the support plates (65) lies in a common plane (130); positioning the jig frame (62) such that the machined surfaces of the support plates (65) contact with a supporting surface (138); fixing pickup device mounting plates (140a, 140b) to the jig frame (62); machining, with respect to the supporting surface (138), the pickup device mounting plates (140a, 140b) such that a surface of each mounting plate (140a, 40b) has a respective predetermined position and orientation with respect to the supporting surface (138); and fixing, to the machined surfaces of the mounting plates (140a, 140b), a respective pickup device (66-72).

Abstract: An infrared countermeasure system comprises a transparent infrared camera dome with an anti-icing surface coating.

Abstract: A temperature insensitive locking apparatus for use with large optical mounts having at least one locking nut having an internal threaded portion adjacent to an internal tapered portion, at least one flexurized spring collet attached to a rigid base structure having an external threaded portion and a plurality of tapered flexures, a pivot shaft engaged with an optical yoke on a rotational axis of symmetry wherein when the internal threads of the locking nut engage with the external threads of the flexurized spring collet an increased level of a radial clamping force is provided around the pivot shaft.

Abstract: A display apparatus is described that comprises an optical ocular part (3) arranged for viewing a scene therethrough, and a waveguide display part (6) arranged for guiding image-bearing light to a transparent display output area (16) thereof and thereat displaying the image. The ocular part and/or the waveguide display part are positioned, or are arranged to be positioned, mutually in register for viewing simultaneously the scene with the displayed image incorporated in it, through the transparent display output area. A focuser part (17) positioned in register with the display output area focuses simultaneously the scene and the incorporated image for focused viewing by a user (13).

Abstract: An aircraft-side aircraft data retrieval system and method, comprising: a data storage device (14) located in a first location, for example a bay (8), in a aircraft (2) adapted to, during a flight, store data acquired during the flight; and wireless apparatus (18) comprising an antenna (28), at least the antenna (28) being located in a second location, for example an undercarriage bay, in the aircraft (2) that is different to the first location, the wireless apparatus (18) adapted to wirelessly transmit, after landing, the stored data to a ground-side data retrieval system (6); the second location (10) being a location that can have a closed or open configuration and which will be in the closed configuration for at least a majority of the flight and in the open configuration, for a purpose other than retrieving the stored data, after the aircraft (2) has landed.

Abstract: An apparatus and method are provided for implementing one or more security services to messages and data being communicated between a first network and a second network. In particular, a network bridge device is provided for applying communications security services to data passing by means of the device from a first network to a second network, the device having a first network interface for linking to the first network, a second network interface for linking to the second network, and a unidirectional link between the first and second network interfaces within the device incorporating a first hardware logic module, configured to apply one or more predetermined data security functions to message data received via the first network interface, and a second hardware logic module, arranged to apply a predetermined scheme for authentication of the source of messages passing through the device.

Abstract: The present invention relates to an electric drive device comprising an electric motor (20) with a stator and a rotor arranged to rotate a drive shaft, wherein said electric motor (20) is arranged to be accommodated in a housing, further comprising opposite gear housings surrounding the electric motor, each containing a transmission configuration, wherein the electric drive device comprises a housing configuration in which the electric motor (20) as well said opposite gear housings (30a, 30b) are accommodated, wherein each gear housing (30a, 30b; 130a, 130b) is attached and hereby locked to said housing configuration. The invention also relates to a motor vehicle.

Abstract: A fiber optic laser for use in high stress environments is provided. The fiber optic laser comprises a hollow spool structure housing a fiber in a spiral groove in an interior surface of said hollow spool structure, wherein the fiber is mechanically supported along an entirety of its length within the hollow spool structure. Fluid channels are formed within the hollow spool structure, wherein a quantity of coolant is movable through the fluid channels to provide high-precision thermal management of the fiber.

Abstract: A two-part fiber optic collimator has a precision adjuster for controlling the position of a spring-biased lens carrier with respect to the collimator's body. An interchangeable fiber optic connector adaptor is attached to the collimator body for accurately positioning the end of a fiber optic cable in the collimator.

Abstract: A method of detecting land mines includes pre-processing a raw laser interferometer image, processing pre-processed image by calculating one or more derivatives having one or more peaks, along vectors extending in at least two different directions, mapping the peaks of said derivatives to create a derivative map, and detecting an anomalous signature in the derivative map.

Abstract: Disclosed is a conduit (4) comprising a conduit wall defining a flow channel through which a fluid may flow and a plurality of further channels (24) through at least part of the conduit wall. Each further channel (24) comprises a first end (20) and a second end (22). The first ends (20) of the further channels (24) are spaced apart along a length of the conduit (4) and comprise openings in fluid communication with the flow channel of the conduit (4). The second ends (22) of the further channels (24) are located proximate to one another (e.g. substantially collocated) such that the distance between the second ends (22) of any two further channels (24) is smaller than the distance between the first ends (20) of those two further channels (24). Pressure sensors (26) may be coupled to the second ends (22) of the further channels, which may be closed.

Abstract: A miniaturized multi-sectioned, directional coupler using a multi-layer MMIC process, the coupler comprising, a monolithic microwave integrated circuit, having a central section with a relatively tight coupling, surrounded by sections of lighter coupling, the relatively tight coupling being comprised of a pair of spiral coupled lines, and the lighter coupling being comprised of meandered edge couple lines with capacitive loading of the lines in several places.

Abstract: A memory system includes c-shell units, PCBs, and a controller logic. The c-shell units are positioned side-by-side adjacent each other. Each c-shell unit has at least two sled-less memory bays and the sled-less memory bays are positioned vertically relative to each other. Each of the sled-less memory bays receives a memory device. A PCB is vertically mounted to a corresponding c-shell unit. The control logic controls access to and from the memory devices so that it manages storing data to the memory devices and retrieving data from the memory devices. Each PCB comprises traces to route signals between the control logic and the memory devices.

Abstract: An apparatus is disclosed for producing an optical display comprising an optical waveguide (1) and a pair (10, 16) of switchable diffraction gratings that are switchable between a diffractive state and a non-diffractive state. A pair of non-switchable diffraction gratings (2, 14) is arranged to receive diffract light from one switchable grating for guided propagation along the optical waveguide and out to the other switchable grating for viewing. The pair of non-switchable gratings are tuned to a first operating wavelength of light, while the pair of switchable gratings are tuned to a different operating wavelength of light to diffract that light into/from a field of view in common with that of the non-switchable gratings such that light of two wavelengths occupies the same field of view.

Abstract: A system and method use an inverse square root function (ISQR) function, in part, to compand and decompand signals. A system includes a companding processor and a transmitter. The companding processor compands input signals into companded signals using a compander function, C{x(n)}. The compander function compands the input signals based, at least in part, on an inverse square root (ISQR) function over at least a portion of a signal amplitude probability density function. The transmitter then transmits the companded signals as electromagnetic wave signals.

Abstract: A system and method for mounting a device to a piece of equipment is presented, and may include a handheld inertial measurement unit (IMU), a computer logic and a mounting interface. The piece of equipment may have a line replaceable unit (LRU) mount that allows a new LRU to be mounted thereon. The mounting interface may be mounted to a LRU mount. The handheld IMU may determine position data with respect to the LRU mount and the piece of equipment. The computer logic may be configured to calculate a positional error value based on the position data to indicate to a user whether corrections need to be made regarding how the new LRU is mounted to the LRU mount before the new LRU is mounted to the LRU mount or whether the new LRU can be mounted to the LRU mount without any corrections.

Abstract: In the method for generating blue laser light with high optical and electrical efficiency, wherein the improvement comprises the step of using a phosphate glass photonic crystal fiber rod as a gain medium.

Abstract: A fiber laser having a thermal controller operatively connected to one or more fiber Bragg gratings is provided. The thermal controller does not impart much or imparts very little mechanical stress or strain to the optical fiber in which the FBGs reside because such forces can alter the FBG performance. Rather, the thermal controller utilizes a thermally conductive semi-solid or non-Newtonian fluid to submerge/suspend a portion of the optical fiber in which FBG resides. Temperature control logic controls whether a thermoelectric heater and cooler should be directed to increase or decrease its temperature. The thermoelectric heater and cooler imparts or removes thermal energy from the FBG to efficiently control its performance without the application of mechanical stress. The fiber laser having a thermal controller generally is able to increase laser output power greater than two times the amount of output power of a similarly fabricated fiber laser free of the thermal controller(s).

Abstract: Methods and apparatus for controlling a bias voltage supplied to an optical modulator, the modulator comprising a biasable component, the biasable component being configurable to be biased by application of the bias voltage (20) such that the modulator operates at quadrature, the method comprising: providing a target for the output power of the modulator, the target for the output power of the modulator being an output power corresponding to the modulator operating at quadrature; applying, to the biasable component, a bias voltage (20) having an initial value of 0V; and, thereafter, varying the bias voltage (20) until the value of the bias voltage (20) is the value that is closest to the initial value and that biases the biasable component so that the output power of the modulator is within a pre-defined range of the target output power.