Abstract: An apparatus for controlling the gain and phase of an input signal input to a power amplifier comprises a gain control loop configured to control the gain of the input signal based on power levels of the input signal and an amplified signal output by the power amplifier, to obtain a predetermined gain of the amplified signal, and a phase control loop configured to obtain an error signal related to a phase difference between a first signal derived from the input and a second signal derived from the amplified signal, and control the phase based on the error signal, to obtain a predetermined phase of the amplified signal. The phase control loop delays the first signal such that the delayed first signal and the second signal used to obtain the error signal correspond to the same part of the input signal. The apparatus may be included in a satellite.

Abstract: A device for guiding and absorbing electromagnetic radiation, the device including: absorbing means for absorbing the electromagnetic radiation; and a coupled to the absorbing means for guiding the electromagnetic radiation to the absorbing means, wherein the waveguide and the absorbing means are formed from a structure including a first cladding layer, a second cladding layer over the first cladding layer, and a quantum-well layer between the first and second cladding layers, the quantum-well layer being formed of a material having a different composition to the first and second cladding layers, wherein the thickness and the composition of the quantum-well layer is optimised to provide an acceptable level of absorption of electromagnetic radiation in the waveguide while providing an appropriate band gap for absorption of the electromagnetic radiation in the absorbing means.

Abstract: An apparatus for controlling the gain and phase of an input signal input to a power amplifier comprises a gain control loop configured to control the gain of the input signal based on power levels of the input signal and an amplified signal output by the power amplifier, to obtain a predetermined gain of the amplified signal, and a phase control loop configured to obtain an error signal related to a phase difference between a first signal derived from the input and a second signal derived from the amplified signal, and control the phase based on the error signal, to obtain a predetermined phase of the amplified signal. The phase control loop delays the first signal such that the delayed first signal and the second signal used to obtain the error signal correspond to the same part of the input signal. The apparatus may be included in a satellite.

Abstract: An ion accelerator includes: an inner magnet having a channel extending through it in an axial direction; an outer magnet extending around the inner magnet, the magnets having like polarities so as to produce a magnetic field having two locations of zero magnetic field strength. The locations are spaced apart in the axial direction; and an anode and a cathode are arranged to generate an electrical potential difference between the locations.

Abstract: An apparatus for use in a SpaceWire-based network is configured to send and receive data packets, and process data included in a received data packet. A header of the received data packet is stored in a buffer while the data is being processed, a processed data packet including the stored header and the processed data is generated, and the processed data packet is transmitted. The header of the received data packet may be modified, and the modified header attached to the processed data to generate the processed data packet. When the data packet is received via a first port, the processed data packet may be transmitted via the first port, or may be transmitted via a second port.

Abstract: A device for guiding and absorbing electromagnetic radiation, the device including: absorbing means for absorbing the electromagnetic radiation; and a coupled to the absorbing means for guiding the electromagnetic radiation to the absorbing means, wherein the waveguide and the absorbing means are formed from a structure including a first cladding layer, a second cladding layer over the first cladding layer, and a quantum-well layer between the first and second cladding layers, the quantum-well layer being formed of a material having a different composition to the first and second cladding layers, wherein the thickness and the composition of the quantum-well layer is optimised to provide an acceptable level of absorption of electromagnetic radiation in the waveguide while providing an appropriate band gap for absorption of the electromagnetic radiation in the absorbing means.

Abstract: A connector includes an outer connection element and an inner connection element. One of the outer connection element and inner connection element includes a plurality of fingers extending at an angle relative to a longitudinal axis of the connector.

Abstract: An apparatus for controlling the gain and phase of an input signal input to a power amplifier comprises a gain control loop configured to control the gain of the input signal based on power levels of the input signal and an amplified signal output by the power amplifier, to obtain a predetermined gain of the amplified signal, and a phase control loop configured to obtain an error signal related to a phase difference between a first signal derived from the input and a second signal derived from the amplified signal, and control the phase based on the error signal, to obtain a predetermined phase of the amplified signal. The phase control loop delays the first signal such that the delayed first signal and the second signal used to obtain the error signal correspond to the same part of the input signal. The apparatus may be included in a satellite.

Abstract: An extendable structure which may be used in space-based applications, for example forming the body of a telescope. The structure is movable between a stowed configuration and an extended configuration, and comprises a plurality of walls arranged to give a polygonal cross-section in the extended configuration. Each wall comprises a plurality of repeating units which are connected by a plurality of hinges. Each repeating unit itself comprises a plurality of sections connected by pluralities of first and second hinges, and in the extended configuration, each of the first hinges lies between two second hinges with the second hinges having axes which are inclined with respect to the first hinge axis.

Abstract: A test arrangement includes a multi-port test interface having a first waveguide coupled to a plurality of second waveguides. The first waveguide is arranged to propagate an input signal and each of the second waveguides is arranged to output the input signal, providing a plurality of test signals to be supplied to a communications apparatus. Such a test interface may also be used to output respective channel signals in a multiplexed signal received from a communications apparatus. The test interface permits the provision and/or monitoring of a large number of channel signals without separate respective connections to the communications apparatus. This may be particularly useful where tests are performed in a constrained space and/or where repeated access to the apparatus is impractical. The simultaneous provision of many channel signals may allow evaluation of co-channel interference.

Abstract: A device comprising: a substrate; a plurality of resonators on the substrate, each of the resonators of the plurality of resonators being resonant at a predetermined wavelength of electromagnetic radiation and at least some of the resonators being arranged to operate in different resonance orders; a waveguide on the substrate, the waveguide being coupled to the plurality of resonators for guiding the electromagnetic radiation to the plurality of resonators, wherein the resonance order of each resonator along the waveguide is optimized to maximize the coupling of light into the resonators.

Abstract: An apparatus is disclosed for a spaceborne or aerial platform having a frequency demultiplexer for frequency demultiplexing a signal corresponding to a range line or an azimuth line of SAR data, and including information about a plurality of target points, into a plurality of frequency channels, and a compression device for performing compression on each frequency channel, each frequency channel signal having information about the same target points. The frequency demultiplexer and the compression device can be implemented in hardware. The apparatus may be used for either or both of the range compression and the azimuth compression of a SAR arrangement on board a spaceborne or aerial platform and the SAR arrangement may generate a plurality of sub-images corresponding to the frequency channels from the SAR raw data. The sub-images may be combined by averaging in order to reduce the volume of memory required to store the SAR data.

Abstract: A spectrometer comprises a substrate and a waveguide on the substrate, the waveguide including an elongate part and a tapered input for guiding electromagnetic radiation to the elongate part. The tapered input includes an input end for receiving the electromagnetic radiation and an output end coupled to the elongate part, the input end being wider than the output end. The spectrometer may further comprise a plurality of resonators coupled to the elongate part of the waveguide.

Abstract: An apparatus for controlling the gain and phase of an input signal input to a power amplifier comprises a gain control loop configured to control the gain of the input signal based on power levels of the input signal and an amplified signal output by the power amplifier, to obtain a predetermined gain of the amplified signal, and a phase control loop configured to obtain an error signal related to a phase difference between a first signal derived from the input and a second signal derived from the amplified signal, and control the phase based on the error signal, to obtain a predetermined phase of the amplified signal. The phase control loop delays the first signal, such that the delayed first signal and the second signal used to obtain the error signal correspond to the same part of the input signal. The apparatus may be included in a satellite.

Abstract: A reflector antenna includes a dual-band waveguide feed and a splashplate support arranged to define a space between the waveguide feed aperture and the splashplate. The dual-band waveguide feed is configured to receive an input signal in a first transmission mode, to convert a transmission mode of an upper frequency band from a first transmission mode to a mixed transmission mode including the first transmission mode and a second transmission mode. The supporting portion can be spaced apart from the aperture of the waveguide feed, and may have a thickness corresponding to half a wavelength of a beam emitted from the aperture.

Abstract: An apparatus for use in a SpaceWire-based network is configured to send and receive data packets, and process data included in a received data packet. A header of the received data packet is stored in a buffer whilst the data is being processed, a processed data packet including the stored header and the processed data is generated, and the processed data packet is transmitted. The header of the received data packet may be modified, and the modified header attached to the processed data to generate the processed data packet. When the data packet is received via a first port, the processed data packet may be transmitted via the first port, or may be transmitted via a second port.

Abstract: A receiving device for receiving a satellite broadcast is disclosed which includes a receiver for receiving a sustaining satellite beam and a controller for switching the receiver to receive a high power content beam in response to a determination that the high power content beam can be received by the receiving device. A communication satellite can transmit the high power content beam to different geographical areas at different times. The sustaining beam allows the receiving device to remain synchronized with the communication satellite when the high power content beam is directed elsewhere. The sustaining beam may be a lower power beam. The determination that the high power content beam can be received may be performed based on information in the sustaining beam.

Abstract: A structure for guiding electromagnetic radiation, including: a substrate; a waveguide provided on the substrate and having a first end for receiving electromagnetic radiation and a second end; and an anti-reflection region provided at the second end of the waveguide on the substrate, the length and the width of the anti-reflection region being optimized to suppress back reflection of radiation that reaches the second end.

Abstract: A device for detecting electromagnetic radiation comprises a waveguide and at least one resonator on a substrate, and a low-refractive index region between each resonator and the substrate. The low-refractive index region has a lower refractive index than a material of the resonator. The low-refractive index region may be annular, and may have a width corresponding to a width of a region in which electromagnetic radiation is concentrated in a whispering-gallery resonant mode. The low-refractive index region may be an air gap between the substrate and the resonator. The device may be a spectrometer for detecting a plurality of predetermined wavelengths of electromagnetic radiation.

Abstract: An article comprises a carbon fibre reinforced plastic (CFRP) substrate, a buffer layer disposed adjacent the substrate, the buffer layer comprising a poly(para-xylylene) polymer; and a moisture barrier coating disposed adjacent the buffer layer.