Abstract: The bias circuit of the present invention can be configured for extremely stiff biasing for Class A circuits, which is solid under heavy RF input overdrive. Alternatively, the circuit may be configured for controlled self biasing for use in Class AB designs.

Abstract: An amplifier pre-distorter method and apparatus squares an input signal and splits the signal into inphase and quadrature parts which are processed to generate a polynominal predistortion signal. This simplifies the apparatus and enables implementation in an application specific integrated circuit.

Abstract: A device for detection of undesired objects on surfaces, for example airport runways co-ordinates sensed data from a plurality of sensor units. With radar sensors, synthetic aperture radar processing is found to be advantageous. A vehicle which is configured with a plurality of sensors may be either remotely controlled or autonomous. It may also be provided with communication equipment and debris retrieval apparatus and that includes both mobile sensing devices and fixed installations. A suitable mobile sensing device and a method for operating the debris detection system are also provided.

Abstract: A method of verifying integrity of an access point on a wireless network comprises registering an access point with a core network, allocating a unique identifier from the network to the access point; recording data including the unique identifier together with a geographical location of the access point; requesting reports relating to access points in the vicinity of a mobile terminal when the mobile terminal sends other data, including the unique identifier as determined by mobile terminals listening to wireless transmissions from said access points, to the core network; and checking data in the reports against recorded data to determine if an access point is genuine

Abstract: Apparatus for producing an amplified Radio Frequency pulse includes a controller for monitoring the output amplified pulse and determining therefrom a correction for a deviation in the characteristics. The correction is applied by a phase shifter or amplitude controller for subsequent pulses. The apparatus is particularly applicable to pulses used by RADAR equipment and allows the use of longer duration pulses. This improves the detection range of the equipment.

Abstract: A web-enabled microcontroller device is provided with both web server functions (310) and generic control and monitoring functions (312). The web-enabled microcontroller device may be embedded in domestic, commercial and industrial hardware. Integrated software for remotely controlling hardware by means of the microcontroller device combines control application code (312) and HTTP server code (310). One implementation of the microcontroller device has a microprocessor coupled to a physical communications unit, a ROM and a RAM. The protocol stack (314) associated with the HTTP server may be permanently coded into the ROM or loaded into the RAM as required. In another implementation, the physical communications unit includes a digital signal processor and a wireless access unit, thereby providing a web-enabled digital wireless access device.

Abstract: A network resilient to at least two points of failure comprises a plurality of nodes. A first path between a source node and a destination node is determined and a second path between a source node and a destination node is determined. The first and second paths are node-disjoint.

Abstract: A phased array radar comprises a first array (2) of detectors (6) in a first dimension; and a second array (1) of detectors (6) in a second, orthogonal, direction. The first array of detectors both transmits (8) and receives (9) and the second array of detectors only receives (7). The first array resolves in range and either azimuth, or elevation; whereas the second array is a staring array that stares at targets at specified ranges determined by the first array, and the second array resolves in the other of elevation or azimuth, accordingly.

Abstract: A method of authenticating access points (1, 2, 3) on a wireless network (4) comprises sending a list of nearest neighbours (2, 3) from a trusted access point (1) to a controller (6). At the trusted access point (1), test data related to each of the listed nearest neighbours is received from the controller. Each neighbour (2, 3) is interrogated using its respective test data and the response compared with an expected response. A reliability indication is returned to the controller (6).

Abstract: An acoustically activated marketing for displaying predefined information in response to predefined data being received. The device is obtained from a retailer and worn as a badge while at the cinema or while listening to the radio or TV. When a specific advertisement is broadcast, the badge interprets part of the sound track and activates the display on the badge. The displayed information may be an advertisement or a message. The predefined data may be broadcast by a commercial broadcasting means, such as a television or radio.

Abstract: A method of spectrum sharing comprises determining a first frequency in a first location area (30) for a channel (15) of a first transmission type; and choosing a second frequency for a channel (1) of a second transmission type on which to transmit in the first location area; wherein the second frequency differs from the first frequency by at least two frequency channels of the first transmission type.

Abstract: An optical data receiver for the distribution and demodulation of compressed TDM data packages comprises, optical distributor means to which the data packages are applied for selective distribution to a plurality of AWG optical demultiplexer/detector arrays, so that each demultiplexer/detector array provides in respect of each data package fed thereto from the optical distributor, a data word the bits of which are presented in parallel.

Abstract: A method of determining the position of a target comprising the steps of: providing a transmitter or a plurality of transmitters to transmit a signal to the target, providing a receiver or a plurality of receivers to receive signals reflected from said target. Determining the time of arrival information of said reflected signal at the or each receiver; using information pertaining to the position of the or each receiver and/or the or each transmitter and with the information obtained determining the target position. Preferably the signal includes a modulated or coded portion unique to the transmitter; and said signal portion is associated with the or each particular transmitter by virtue of said signal portion. The signal maybe a mobile phone transmission, DAB, digital TV, digital Radio or digital satellite transmissions.

Abstract: Method and apparatus for providing accurately synchronized timing signals at mutually distant locations employs a GPS or similar receiver at each location. These receivers are interconnected by a communications network, and exchange data over the network to agree a common timing reference.

Abstract: A dual polarised antenna 1 has two types of antenna elements combined. Each type of antenna element is formed on a planar substrate. The substrates are furnished with inter-engaging slots to enable assembly of the elements. Signal feeds are connected to the active parts of the elements by means of connection points furnished at off axis positions. The off-axis positions for connection enable an arrangement in which the locus of the effective phase centres of the antenna element scan be co-located yielding a convenient arrangement with good performance.

Abstract: A router device has a plurality of ingress line interface cards (LICs), a plurality of egress LIC's, a backplane and a controller. Transmission of signals from the ingress LICs to the controller, and from the controller to each of the ingress and egress LICs takes place across the backplane. Each ingress LIC is provided with a dedicated timeslot in which it can send information to the controller via connection. Information is sent in a slice within the dedicated timeslot and each egress LIC ignores data sent by a given ingress LIC within the timeslot assigned to said ingress LIC. A similar system is used for transmission of communications from the controller to the LICs. It is thus possible to avoid provision of additional, dedicated communications paths between the LICs (ingress and egress) and the controller.

Abstract: Methods and apparatus are provided for forming an image (68) of a scene (18) comprising a source of emitted or reflected light. The scene is illuminated (54) and a first image corresponding to the illuminated scene is recorded. Illumination is ceased, and a second image of the emitted or reflected light, corresponding to the non-illuminated scene, is recorded. The second image is used to generate a marker in the first image, said marker indicating the position of the emitted or reflected light.

Abstract: In a method for cell level scheduling for handling multicast traffic in routing devices, such as cross-bar switches having, a plurality of ingress line interface cards (LICs), a plurality of egress LICs, a cross-bar and a controller, multicast and unicast data traffic passes from the ingress LICs via the cross-bar to the egress LICs. A given multicast data packet is sent from a given ingress LIC to a predetermined set of egress LICs known as the fanout of the given packet. Each ingress LIC has an associated rate of send opportunities. The method allows multicast send opportunities to be spread as evenly as possible over cell periods, by invoking a conventional unicast scheduling scheme when one or more multicast send opportunities are present. The schedule is filled out with the fanouts of multicast packets in accordance with the send priority associated with the respective ingress LICs upon which each of the respective multicast packets is queued.

Abstract: A directional, wideband, planar antenna arrangement is a class of Vivaldi aerial constructed as a plurality of conductive layers disposed on at least one substrate layer. The conductive layers are arranged to form a flared notch, which widens from a closed end to an open end, and is arranged to conform to a hybrid curve. The hybrid curve comprises a plurality of self-similar curve sections, and, as the flare widens, each successive curve section is scaled up by a scaling factor and joined at its wider end with a neighboring curve section. The hybrid flared notch can also be implemented in antipodal and balanced antipodal Vivaldi aerials.

Abstract: A method of compressing data, wherein said data is in the form of discrete units, by determining an overall code specific to the units, comprising the steps of: a) grouping the units in terms of a common behavior pattern; b) for each said group of units, assigning a group specific code, the sizes of said group code being ordered according to the probability of the unit occurring; c) assigning a unit identifier code which is specific to identify an individual character within the group, the overall code comprising of the cocatenated group specific and identifier codes, characterized wherein step c), the identifier code is of the minimum size to allow for each unit which could occur in that group to be assigned specifically.