Abstract: An optical selector arrangement (22), comprising: a first set of optical ports (30), having a first number of optical ports, the first number being greater than or equal to 2; a second set of optical ports (42), having a second number of optical ports, the second number being greater than the first number; the second set of optical ports being for communicating with the first set of optical ports, a selector interface (40) for the optical selector arrangement, the selector interface comprising the second set of optical ports (42), a part of the optical selector arrangement functioning as a selector (44), the selector being arranged to selectively optically couple the first set of optical ports (30) to a set of ports of the second set of optical ports (42) of the selector interface, the selector (44) being rotatable relative to the selector interface (40) to facilitate the selection by optically aligning the first set of optical ports (30) to the second set of optical ports (42) of the selector interface (40);

Abstract: An optical transmitter (201) comprising: a laser diode (102) for transmitting an optical signal; a first temperature sensor (106) configured to measure a temperature at or proximate to the laser diode (102); a second temperature sensor (202) configured to measure a temperature of an environment in which the optical transmitter (201) is operating; a thermoelectric device (208) configured to apply heating or cooling to the laser diode (102); and a controller (212) configured to, using the temperature measurements taken by the first temperature sensor (106) and the second temperature sensor (202), control the thermoelectric device (208) to heat or cool the laser diode (102).

Abstract: A fiber-radio communication network includes a base station (300) and wireless access nodes (100) coupled by fiber optic cables (125). The base station (300) includes a switch module (320) arranged to switch Ethernet signals on a local area network, and a media converter rack module (310) comprising media converter units MC1-MC6 arranged to convert between a baseband Ethernet signal carried by the fiber optic cables (125) and an Ethernet digital signal for the switch. The wireless access node (100) comprises a media converter module (120) which converts between a baseband Ethernet signal carried by the fiber optic cables and an Ethernet digital signal; and a wireless access point module (110) comprising a local modem which converts between the Ethernet digital signal received over the fiber optic cables and a wireless transmission in a 60 GHz range for wireless communication with a client terminal (400) in the vicinity of the wireless access node (100).

Abstract: An aircraft-side aircraft data retrieval system and method, comprising: a data storage device (14) located in an aircraft (2) adapted to, during a flight, store data acquired during the flight; a transmission element (50), for example a dielectric filled hole or a coaxial transmission line assembly, in an external panel (9) of the aircraft (2); and wireless apparatus (18) adapted to wirelessly transmit, after the aircraft (2) has landed, the stored data to a ground-side data retrieval system (6) via the transmission element (50).

Abstract: A method and apparatus for operating an optical rotating joint (2); comprising: routing optical signals through an optical rotating joint (2) by using a first optical circulator (64) on a first side of the optical rotating joint (2) to receive an optical signal and direct the optical signal onward to a first side of the optical rotating joint (2), and using a second optical circulator (93) on a second side of the optical rotating joint (2) to receive the optical signal from the second side of the optical rotating joint (2) and direct it onwards. The signals may be sensor control signals or sensor output signals to/from a plurality of sensors (26, 28, 30), for example camera sensors. The apparatus may further comprise one or more wavelength division multiplexers (68, 94) and/or wavelength division demultiplexers (66, 95).

Abstract: A method and apparatus for operating an optical rotating joint (2); comprising: providing redundancy for camera sensor signals to be passed through an optical rotating joint (2) by: (i) passing signals from a plurality of camera sensors (28, 30) via an optical changeover switching arrangement (70) to the optical rotating joint (2); and/or (ii) passing signals for a plurality of camera sensors (28, 30) toward the camera sensors (28, 30) from the optical rotating joint (2) via an optical changeover switching arrangement (70). The signals may be sensor control signals or sensor output signals to/from a plurality of sensors (26, 28, 30), for example camera sensors. The apparatus may further comprise one or more wavelength division multiplexers (68, 94) and/or wavelength division demultiplexers (66, 95).

Abstract: A Peltier effect heat transfer system (208) comprising: a plurality of heat transfer elements (301-308); wherein each heat transfer element (301-308) comprises at least one semiconductor element pair arranged to yield Peltier effect heat transfer, each semiconductor element pair comprising a P-doped semiconductor element (408) and an N-doped semiconductor element (410); and the heat transfer elements (301-308) are independent such that each heat transfer element (301-308) can be activated so as to yield Peltier effect heat transfer independently of each other heat transfer element (301-308).

Abstract: Signal processing apparatus located in and/or mounted on an entity (e.g. an aircraft), the signal processing apparatus comprising: a first module; a second module connected to the first module such that signals may be sent between those modules; one or more amplifiers configured to amplify signals sent between the modules; and one or more optical fibres. The first module is located at a first location in/on the entity. The second module and the one or more amplifiers are located at a second location in/on the entity. The first location and the second location are spatially separate, i.e. remote from one another. The optical fibre(s) couple together the first and the second locations such that a signal sent between those locations is sent via the optical fibre(s).

Abstract: An optical transmitter (201) comprising: a laser diode (102) for transmitting an optical signal; a first temperature sensor (106) configured to measure a temperature at or proximate to the laser diode (102); a second temperature sensor (202) configured to measure a temperature of an environment in which the optical transmitter (201) is operating; a thermoelectric device (208) configured to apply heating or cooling to the laser diode (102); and a controller (212) configured to, using the temperature measurements taken by the first temperature sensor (106) and the second temperature sensor (202), control the thermoelectric device (208) to heat or cool the laser diode (102).

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: A fibre-radio communication network includes a base station (300) and wireless access nodes (100) coupled by fibre optic cables (125). The base station (300) includes a switch module (320) arranged to switch Ethernet signals on a local area network, and a media converter rack module (310) comprising media converter units MC1-MC6 arranged to convert between a baseband Ethernet signal carried by the fibre optic cables (125) and an Ethernet digital signal for the switch. The wireless access node (100) comprises a media converter module (120) which converts between a baseband Ethernet signal carried by the fibre optic cables and an Ethernet digital signal; and a wireless access point module (110) comprising a local modem which converts between the Ethernet digital signal received over the fibre optic cables and a wireless transmission in a 60 GHz range for wireless communication with a client terminal (400) in the vicinity of the wireless access node (100).

Abstract: An optical rotating joint installation; comprising: a drive shaft for a rotating interface, the drive shaft comprising a hollow central bore; and an optical rotating joint located in the hollow central bore. The proportion of the cross-sectional area of the material retained in the annular section of the drive shaft is preferably greater than or equal to 50%, more preferably 60%, yet more preferably 75%. The diameter of the hollow central bore is preferably less than or equal to 20 mm, more preferably 16 mm. The optical rotating joint installation may be provided as a retro-fit to replace an existing solid drive shaft that does not have an optical rotating joint, for example by hollowing out the existing solid drive shaft or by replacing the existing solid drive shaft with a drive shaft with a hollow central bore.

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: A bidirectional radio frequency communication unit includes: a transmit modem; a receive modem; an RF transceiver circuit; a coupling waveguide arrangement; and an antenna. The RF transceiver circuit transmits and receives at RF frequencies greater than or equal to 50 GHz. At least a majority of the RF transceiver circuit is provided on a single multilayer PCB. The coupling waveguide arrangement is provided in the form of respective transmit and receive waveguides provided within a diplexer that has a common antenna coupling port and is in the form of a block. The multilayer PCB and the diplexer form a laminated structure; and transition interfaces between the RF transceiver circuit and the waveguide include one or more buried layer probe elements in a buried layer of the multilayer PCB.

Abstract: An aircraft-side aircraft data retrieval system and method, comprising: a data storage device (14) located in an aircraft (2) adapted to, during a flight, store data acquired during the flight; a transmission element (50), for example a dielectric filled hole or a coaxial transmission line assembly, in an external panel (9) of the aircraft (2); and wireless apparatus (18) adapted to wirelessly transmit, after the aircraft (2) has landed, the stored data to a ground-side data retrieval system (6) via the transmission element (50).

Abstract: An aircraft-side aircraft data retrieval system and method, comprising: a data storage device (14) located in a aircraft (2) adapted to, during a flight, store data acquired during the flight; and wireless apparatus (18) adapted to wirelessly transmit, after the aircraft (2) has landed, the stored data to a ground-side data retrieval system (6), at a frequency in a range selected from the following ranges: (i) 50-70 GHz, (ii) 110-120 GHz, (iii) 170-190 GHz, (iv) 310-330 GHz, (v) 22-24 GHz. for example in the range of 50-70 GHz or more particularly in the range of 55-65 GHz. The data storage device (14) may be located in an electromagnetically sealed bay (8) of the aircraft (2). An antenna (28) of the wireless apparatus (18) may be in a location, for example an undercarriage bay, that is in an open configuration, for a purpose other than retrieving the stored data, after the aircraft (2) has landed.

Abstract: There is disclosed an integrated lighting and network-interface device comprising a housing defining an aperture, a lens supported at the aperture for allowing light and 55-65 GHz radiation to pass therethrough, a light source, a transceiver module having an antenna unit, the transceiver module being adapted for connection to an optic fibre port, and being for operation at at least one centre frequency between 55 GHz and 65 GHz, wherein the light source and the antenna unit are disposed in the housing and arranged to radiate through the lens.

Abstract: An antenna system, comprising: a phased array antenna (4); and a dielectric lens arrangement (6), for example a single solid dielectric lens (6) comprising a substantially spherical convex surface (12) and a concave surface (14); wherein the dielectric lens arrangement (6) is arranged to magnify the effective aperture of the phased array antenna (4). The concave surface (14) is positioned within the near field of the phased array antenna (4). The phased array antenna (4) is operated at a frequency greater than or equal to 50 GHz. The antenna system retains some ability to electronically scan the beam. The antenna system may be for transmission and/or reception. The antenna system may be used for example for communication between two vehicles.

Abstract: An optical rotating joint installation; comprising: a drive shaft for a rotating interface, the drive shaft comprising a hollow central bore; and an optical rotating joint located in the hollow central bore. The proportion of the cross-sectional area of the material retained in the annular section of the drive shaft is preferably greater than or equal to 50%, more preferably 60%, yet more preferably 75%. The diameter of the hollow central bore is preferably less than or equal to 20 mm, more preferably 16 mm. The optical rotating joint installation may be provided as a retro-fit to replace an existing solid drive shaft that does not have an optical rotating joint, for example by hollowing out the existing solid drive shaft or by replacing the existing solid drive shaft with a drive shaft with a hollow central bore.

Abstract: A method and apparatus for operating an optical rotating joint (2); comprising: providing redundancy for camera sensor signals to be passed through an optical rotating joint (2) by: (i) passing signals from a plurality of camera sensors (28, 30) via an optical changeover switching arrangement (70) to the optical rotating joint (2); and/or (ii) passing signals for a plurality of camera sensors (28, 30) toward the camera sensors (28, 30) from the optical rotating joint (2) via an optical changeover switching arrangement (70). The signals may be sensor control signals or sensor output signals to/from a plurality of sensors (26, 28, 30), for example camera sensors. The apparatus may further comprise one or more wavelength division multiplexers (68, 94) and/or wavelength division demultiplexers (66, 95).