Abstract: Apparatuses and methods for controlling an object spinning at a first rate in a first direction. The apparatus includes a swash plate, a rotor, a spin actuator, a roll actuator, and a pitch actuator. The rotor is coupled to the swash plate. The spin actuator is coupled to the rotor and is configured to spin the rotor in a second direction opposite the first direction at a second rate. The roll actuator is coupled to the rotor and is configured to displace the swash plate along a longitudinal axis. The pitch actuator is coupled to the rotor and is configured to tilt the swash plate in a tilt direction about the longitudinal axis, the tilt direction being adjustable by adjusting the second rate relative to the first rate. The roll actuator may be coupled to the pitch actuator so that the pitch actuator keeps a substantially identical orientation with the swash plate as the swash plate is displaced along the longitudinal axis by the roll actuator.

Abstract: A transmission line antenna assembly having a substantially continuous bandwidth from the microwave region of the electromagnetic spectrum to the VHF region of the spectrum. The antenna assembly includes at least one balanced transmission line antenna element of high-temperature superconductor material supported by a substrate, an antenna cavity supporting the substrate and containing a thermally-conductive electromagnetic-energy-absorbing material therein, and a cryogenic cooler for cooling the antenna element to a temperature at which it exhibits superconductivity.

Abstract: A clock splitter circuit for providing a Single Event Upset (SEU) tolerant clock signals to latches in a space-based environment. The splitter circuit includes an event offset delay. The event offset delay receives an undelayed clock signal and generates an undelayed inverted clock, a delayed clock signal and an inverted delayed clock signal. The delayed clock signal and the inverted delayed clock signal are delayed by the known duration of Single Event Effects (SEE) on logic. The delayed and undelayed clock signals are passed to a pair of event blocking filters which block any disturbance in the undelayed and/or undelayed clock signals. The event blocking filters each generate a pair of in-phase inverted output signals. The event blocking filters are designed such that both pairs of outputs may not be low simultaneously.

Abstract: Faraday Rotation causes rotation of the plane of polarization of plane polarised radiation emitted by a radar e.g. a synthetic aperture radar and, if returns polarized in orthogonal planes are measured at the synthetic aperture radar in order to determine polarimetric characteristics of the ground, which could show up features of the ground such as crop patterns, the measurements made at the SAR are contaminated by the Faraday Rotation. In the invention, the transmitted plane polarized beam is pre-rotated in transmitter 9, the radar returns in receiver 13 are mathematically adjusted in signal formatting 14, 15 to compensate for just the pre-rotated angle, to produce data streams on downlink 16 uncontaminated by the Faraday Rotation.

Abstract: The present invention features a cross-element, steerable, scanning meander line loaded (MLA) antenna with circular polarization. The transmission lines comprise a plurality of alternating or stepped impedance sections with the high impedance elements acting as active antenna elements. The impedance varies depending upon the spacing from the moveable ground plane. The orthogonal MLA elements allow the application of an in-phase and a 90° shifted signal, thus each linear array radiates a circularly polarized RF signal. Controlling the spacing between the ground plane and transmission line provides relative phase control between the active elements and thereby phased-array directional control of the antenna. Forming a two-dimensional array of these linear arrays, produces a compact, low-cost, scanning, phased-array antenna.

Abstract: A method of forming a substantially planar, multi-layer, composite article that comprises a plastics materials reinforced with fibers that extend substantially continuously in one direction in the plane of each layer is provided. The majority of the layers are aligned in a main direction B and the article (20a) is disposed over a contoured surface of a forming tool (6). The article (20a) is constrained against movement in a direction perpendicular to the plane of the main direction layers and forces applied to the article (20a) in the plain thereof in a direction substantially perpendicular to the main direction of the fibers. The article (20a) is thereby urged into conformity with the contoured surface of the tool (6) while substantially maintaining the continuity of the fibers.

Abstract: A computationally efficient digital signal processing (DSP) system is provided for multiplexing/demultiplexing a large number of closely spaced FDM channels. Sub-band definition filtering divides the FDM channel band, comprised of N channels into K sub-bands, in order to reduce the dimension of polyphase filter fast-Fourier transform for completing the multiplexing/demultiplexing. This reduces the order of the required prototype by a factor proportional to K and allows small size, lightweight DSP implementations.

Abstract: An actuator system (10, 100, 200) for use in an aircraft control or operating system, comprising a controller (12) operable in response to an input for generating a control signal, and an electrical actuator (20) responsive to the control signal for operating an aircraft flight control surface or other aircraft apparatus. A tab (24; 124) for aerodynamically assisting the electrical actuator is also provided in order to reduce the load on the electrical actuator in use.

Abstract: A single-event upset tolerant sense latch circuit for sense amplifiers is disclosed. The single-event upset tolerant sense latch circuit includes a first set of isolation transistors, a second set of isolation transistors, a first set of dual-path inverters, a second set of dual-path inverters, and an isolation transistor. The first set of isolation transistors is coupled to a first bitline, and the second set of isolation transistors is coupled to a second bitline. The second bitline is complementary to the first bitline. The first set of dual-path inverters is coupled to the first set of isolation transistors, and the first set of dual-path inverters includes a first transistor connected to a second transistor in series along with a third transistor connected to a fourth transistor in series.

Abstract: An aircraft landing gear comprises four mounting members 14, 15, 18, 19 attached to an airframe of the aircraft via attachments 14a, 15a, 16a. One of the attachments 16a is in the form of a leaf spring 30 which can flex upwards and downwards but is non-displaceable in a side-to-side direction thereby reducing induced loading in the mounting members resulting from airframe deflection.

Abstract: The machine comprises a forming station 18 for receiving a piece of fabric 28 which is shaped at the forming station by a cutter 26. A plurality of lay up stations 40, 42 is provided and a roller 48 is used to carry the shaped fabric 28a from the forming station 18 to one or other of the lay-up stations 40,42. The roller 48 lays the shaped fabric in position at the lay-up station to form part of a laminate at that station. The process is repeated to produce a laminate at the remaining lay-up station. A pick-up device 34 is provided for picking up scrap material left as a peripheral band 36 around the shaped fabric 28a.

Abstract: A gyroscope for sensing rate on at least two axes includes a substantially planar vibratory resonator having a ring or hoop like shape, carrier mode drive means for causing the resonator to vibrate in a Cos n1&thgr; in-plane carrier mode where n1 has an integer value of 2 or more. The gyroscope also includes support means for flexibly supporting the resonator, carrier mode pick off means for sensing in-plane movement of the resonator, X axis response mode pick off means for sensing out-of-plane Cos n&thgr; response mode movement of the resonator in response to rotation of the gyroscope around the X axis, where n has a value of n1+1 or n1−1, and Y axis response mode pick off means for sensing out-of-plane Sin n&thgr; response mode movement of the resonator in response to rotation of the gyroscope about the Y axis where n has a value n1+1 or n1−1, identical to that for the X axis response mode.

Abstract: The comparators described herein comprise bit manipulation cells of a number of logic cells each built up of AND, OR etc. logic gates interconnected in parallel to make up one or more layers and do not rely on clocks, instead operating asynchronously. This makes the comparators highly robust and fault tolerant, and well suited for use as binary neurons in high integrity systems. They are less susceptible to radio frequency interference induced data corruption than alternative register-based implementations. Planar Hamming comparators capable of comparing two dimensional input arrays are also described.

Abstract: In an integrated circuit package, the density of the I/O leads is increased by implementing the I/O leads by means of flexible circuits. Flexible circuits comprise thin sheets of insulating material on which the I/O leads are formed by photoetching. A conducting film is provided on the opposite side of the insulating film from I/O leads. To make the circuit package, the outer portions of the substrate of a quad pack are trimmed back to the contact pads on each side of the integrated circuit in the quad pack. The conductors of the flexible circuits are then soldered to the contacts of the contact pads.

Abstract: A method of forming a structural airframe component for an aircraft and an airframe structural component The method includes placing at least two components (1,2) in abutting relationship with each other and joining them together by friction stir butt welding (3), and the structural airframe component comprises a component manufactured according to the method of the invention.

Abstract: A single event upset hardened latch circuit is disclosed. The single event hardened latch circuit includes a first dual-port inverter and a second dual-port inverter. An input is coupled to the first dual-port inverter via a first set of pass gates. The first dual-port inverter is coupled to the second dual-port inverter via a second set of pass gates. The output is connected to the first and second dual-port inverters.

Abstract: A meander line loaded antenna provides a wide instantaneous bandwidth with a first planar conductor extending orthogonally from a ground plane, a second planar conductor substantially parallel to the ground plane and separated from the first planar conductor by a gap, a meander line interconnecting the first and second planar conductors across the gap, and a third conductor connecting the second planar conductor to ground. A fourth conductor provides enhanced capacitance between the first and second planar conductors. The antenna may be arranged in opposed pairs, and also as two orthogonally opposed pairs for enabling circular polarization.

Abstract: A structural joint for the transmission and control of high current flows in a carbon fiber or carbon fiber hybrid composite structure, said joint including at least two composite structures comprising a multiplicity of resin bonded carbon fiber plies, an adhesive applied there between and capable of conducting high currents said adhesive comprising a conductive carrier film comprising carbon fibers, wherein the electrical conductivity of the adhesive is comparable with that of the adjacent composite structures.

Abstract: The durability of a bonded aluminium alloy and/or Alclad (Trade Mark) material joint can be improved by a two stage pre-treatment process in which after the surfaces to be joined have been degreased, a first solution BTESE and/or BTMSE in water, with or without methanol and/or ethanol, is applied to the degreased surfaces dried and coated with a second solution of &ggr;-glycidoxypropyltrimethoxysilane, an amino silane, &ggr;-aminopropyltriethoxysilane and/or trimethoxyvinylsilane in water with or without methanol and/or ethanol and drying prior to the application of an epoxy adhesive coating to the dried second solution surfaces, bonding and curing.

Abstract: A beam steerer for steering a microwave beam comprises a body of magnetic material having an aperture and magnetic coils for applying a gradient of magnetization across the aperture. Tapered slots extending from the magnetic coils towards a central region of the aperture are filled with a material having a lower magnetic permeability than the magnetic material of the body. Lower reluctance paths available through the central region of the aperture allow more magnetic flux from the magnetic coils to penetrate through the central region than would be the case in a body of uniform material composition.