Abstract: A radio receiver accumulates, over all hops of a frequency hopping cycle, digital samples of a carrier signal correlated with a spreading sequence, and performs a Fourier transformation of the accumulated digital samples to generate output data representative of data conveyed by the carrier signal and/or the time of receipt of the carrier signal. The receiver includes a processor arranged to synchronize itself with the frequency hopping cycle and with the spreading sequence at each predetermined value of frequency, by repeating the correlation at different phases of the hopping sequence and of the spreading sequence so as to maximize the output data The correlation and accumulation are performed at a higher sampling rate over a high-resolution portion of one spreading sequence cycle than over the remainder of that spreading sequence cycle.

Abstract: The invention relates to a compass or direction determination device comprising one or more rotation sensitive sensors and means for rotating the one or more rotation sensitive sensors, wherein the means for rotating is configured to produce two or more rotation speeds of the one or more rotation sensitive sensors during a single direction determination operation.

Abstract: A method of processing video comprising a succession of images of a scene to detect movement of an object in the scene, comprising storing a matrix of bytes each representing the difference in intensity of a respective pixel between temporally adjacent images, creating from those bytes a histogram of the frequency at each of a range of positive and negative values of the intensity difference, locating the limits of a central peak of the frequency distribution in the histogram so as to include in the central peak changes due to illumination change and repetitive motions in the background of the scene, determining the proportion of bytes in the remainder of the distribution that are in tails of the distribution on each side of the central peak, repeating the aforesaid process for each successive pair of temporally adjacent images, and providing an output indicative of a moving object and not indicative of illumination change or repetitive motions, in the event that that proportion meets a predetermined criterio

Abstract: A method of manufacturing a ball grid array, BGA, integrated circuit package, comprising forming a double sided printed circuit board, PCB, with blind vias interconnecting electrically the circuits on the opposed surfaces of the PCB, with at least one through-hole to allow fluid or gas to pass through the PCB, and an integrated circuit connected to the printed circuit on one side of the PCB; soldering a lid onto the said one side of the PCB to enclose the integrated circuit, whilst allowing thermally expanding gas or fluid to escape through the or each through-hole, whereby to form a package which is hermetically sealed except for the or each through-hole, and which has a cavity between the integrated circuit and the lid; applying a BGA to the side of the PCB opposed to the said one side, whereby to solder the balls of the BGA to respective portions of the printed circuit and to align one of the balls axially with each through-hole; and soldering the ball or balls into the through-hole, or into each respectiv

Abstract: A method of manufacturing a semiconductor device suitable for optoelectronic switching in response to light of wavelengths in the range 1200 nm to 1600 nm, comprising forming an undoped InGaAs layer on an insulative semiconductor substrate and bonded on opposed sides to a pair of electrical contact layers adapted to constitute the electrodes of a switch, comprising forming the bulk point defects by irradiating the InGaAs layer with Nitrogen ions.

Abstract: A signal processor performs a signal transform of a signal, and comprises a signal demodulator for demodulating said signal by a first chirp signal having a first chirp rate to obtain a reduced bandwidth chirped signal, a filter for filtering the reduced bandwidth chirped signal and delaying the reduced bandwidth chirped signal by an interval proportional to a reciprocal of said first chirp rate, a signal modulator for modulating said filtered signal by a second chirp signal having a second chirp rate to obtain an increased bandwidth chirped signal and to provide a time domain output spectrum of said signal, and wherein each of said first chirp signal and said second chirp signal is a complex signal representing a linear frequency modulated chirp.

Abstract: An infra-red sensor comprising an infra-red lens, an infra-red detector and a processing and control circuit connected to the detector and arranged to provide an output infrared image signal, a heat extraction device for dissipating excess heat from the sensor, and a passive thermal distribution system comprising at least one first heat pipe linking the processing and control circuit board thermally to the heat extraction device, and at least one second heat pipe linking the lens thermally to the processing and control circuit.

Abstract: A method of recovering a clock signal from a digital signal in a receiver includes generating a representation of an eye diagram from symbols of the digital signal, in which the symbols are sampled at a sample rate such that the representation of the eye diagram is generated by a plurality of samples. The generated representation is converted into an array of data elements having a first set of data corresponding to the plurality of samples, and a second set of data representing a plurality of data bins. A plurality of measurements are performed on the array of data elements and/or the eye diagram to obtain a plurality of measurement outputs corresponding to the plurality of samples, which are combined at each sample. A sample is selected as a clock sample based on results of the combination.

Abstract: The invention relates to an imaging method and system for providing acoustic images of a surface and more particularly, but not exclusively, to acoustic imaging of a surface within a confined space. Also described are an acoustic probe and a transmit/receive sensor array configuration to implement the imaging method and system. The probe has an array of acoustic transmitters arranged in juxtaposed or spaced relationship around at least a portion of the circumferential surface of the probe, and an array of acoustic receivers also disposed around at least a portion of its circumferential surface. A beam-former is used for focussing and steering the acoustic beams from the acoustic transmitter array onto portions of the structure to be examined and for focussing and steering the receive beams onto said surface portions, said beam-former adapted to cause the acoustic transmit beams to be focussed in a plane orthogonal to the plane used to focus the receive beams.

Abstract: A method of manufacturing an integrated circuit, IC, package comprising radio frequency, RF, components, the method comprising: electrically connecting a printed circuit pattern on an external major surface of an IC assembly to an RF testing motherboard by bringing them together with an interposed adaptor layer, the adaptor layer comprising a double-sided PCB, printed circuit board, with conductive vias between its printed circuit layers; RF testing the IC assembly using the RF testing motherboard, while RF tuning components of the IC assembly; and separating the IC assembly and connecting its major surface to a solder ball grid array, BGA, which has substantially the same RF impedance as the adaptor at RF signal paths from the IC assembly to the BGA.

Abstract: An assembly comprising a first printed circuit board, PCB, with a ball grid array, BGA, on its underside, a second PCB facing the first PCB and having at least one through-hole between its top and bottom surfaces, its top surface printed with a circuit pattern bonded to the BGA, a heat sink layer facing the bottom surface of the second PCB and having at least one thermally-conductive pin projecting normally into the through-hole or a respective one of the through-holes in the second PCB, and, for each pin, a thermally-conductive stud of the same cross-section as the pin, bonded to the BGA and disposed within the through-hole between the pin and the first PCB in thermal contact with the pin.

Abstract: A warning unit for attachment to a handheld firearm comprises an attachment device for attachment to a firearm, a light source, and a digitally manipulable input device operable to enable selection of a mode of operation. The warning unit is capable of being operated in at least a narrow divergence mode, and a wide divergence mode wherein, in the narrow divergence mode, the warning unit is operable to emit a beam of light of a lower divergence than in the wide divergence mode.

Abstract: A temperature activated switching circuit 100, comprising a temperature activated switch U1 for switching an output 102 at a threshold temperature, the temperature activated switch U1 having at least one power input VCC for receiving power; and power switching circuitry for connecting a power source to said power input VCC of the temperature activated switch U1, the power source being initially disconnected from the power input VCC, and the power switching circuitry being configured to connect said power source to the power input VCC based on a detected temperature, in order to power up the temperature activated switch U1 before said detected temperature reaches said threshold temperature.

Abstract: A strip-map Synthetic Aperture Radar (SAR) auto-focus image generation process is provided. Batches of raw radar return data are processed in order to form batch images which each have a valid region between invalid regions. The process determines an estimate of the first derivative of a phase error at an end of the valid region, determines a time-shift corresponding to that estimate and uses that information in determining a starting point for the next batch of raw radar return data.

Abstract: A microwave circuit package having a ball grid array, BGA, soldered on to a planar major surface of a metal housing of the package for the electrical connection of the ports of the microwave circuit through RF signal paths to an adjacent electrical device. Each of the RF signal paths comprises a pin electrically connected to a respective port of the microwave circuit package, projecting normally through an opening in the said major surface from which it is electrically insulated, and soldered to a ball of the BGA; the pin and the surrounding balls of the BGA, which are soldered to the metal housing, constituting a coaxial RF signal path.

Abstract: A method of manufacturing an integrated circuit, IC, package comprising radio frequency, RF, components, the method comprising: electrically connecting a printed circuit pattern on an external major surface of an IC assembly to an RF testing motherboard by bringing them together with an interposed adaptor layer, the adaptor layer comprising a double-sided PCB, printed circuit board, with conductive vias between its printed circuit layers; RF testing the IC assembly using the RF testing motherboard, whilst RF tuning components of the IC assembly; and separating the IC assembly and connecting its major surface to a solder ball grid array, BGA, which has substantially the same RF impedance as the adaptor at RF signal paths from the IC assembly to the BGA.

Abstract: A mechanical linkage, for use on original equipment or for replacement of existing hydraulic ram based actuators, comprises a rotary to linear transmission. The transmission provides two co-rotatable capstans of different diameters, and two idler wheels spaced on a longitudinally slidable linkage. The capstans are linked to a first of the idler wheels by means of a pulley line wound from the first capstan, around the wheel, and then back to the second capstan. The first capstan is also linked by means of a pulley line to the second idler wheel, and the second capstan likewise to the second idler wheel by a third pulley line. The difference in diameters causes a differential winding of the various lengths of pulley line between the idler wheels and the capstans, which urges the linkage to slide relative to the capstans. Cooperation of the two capstan/idler wheel combinations compensates for possible backlash.

Abstract: A method of analyzing return signals of successive range cells in a scene using constant false alarm rate adaptive control comprising, for each successive range cell in turn is disclosed mathematically. The return signal is processed mathematically and averaged over a predetermined number of cells near that cell. A first variable factor and the return signal for that cell, to derive a first result. The first variable is adapted depending upon that first result. A second variable factor is derived in accordance with a predetermined relationship between the first and second factors are mathematically processed. The second factor is mathematically processed. The second averaged return signal and the return signal for the cell, to derive a second result. The second result is used as an indication of the presence of an object of interest in the scene.

Abstract: A radio receiver arranged to sample an input signal comprising a carrier signal modulated by a predetermined spreading sequence of pseudo-noise code symbols or chips that is stored in the receiver, the carrier signal frequency hopping between predetermined values in a predetermined sequence which is repeated cyclically and is stored in the receiver; the receiver being arranged to accumulate, over all the hops of the frequency hopping cycle, digital samples of the input signal correlated with the spreading sequence, and to perform a Fourier transformation of the accumulated digital samples to generate output data representative of data conveyed by the input signal and/or the time of receipt of the input signal; the receiver comprising a processor arranged to synchronise itself with the frequency hopping cycle and with the spreading sequence at each predetermined value of frequency, by repeating the correlation at different phases of the hopping sequence and of the spreading sequence such as to maximise the out

Abstract: A steerable projectile (30) comprises a body portion (32) and a nose portion (34). The nose portion and body portion are substantially coaxially arranged and rotatable relative to one another about their co-axis. The nose portion further comprises an asymmetric formation (36) operable to enable the projectile to be subjected to off-axis drag during flight.