- Buyers Guide
Military Microwaves Supplement
Recent Advances in Radar Technology
Using Calibration to Optimize Performance in Crucial Measurements
AMSAR Moves Forward
E urope's three nation (France, Germany and the UK) Airborne Multi-role Solid-state Active-array Radar (AMSAR) has successfully passed its Phase 2A Critical Milestone Review (CMR), paving the way for the construction and testing of a Core Antenna Radar (CAR) demonstrator. Intended to develop and maintain a European active, electronically scanned radar capability, AMSAR involves BAE Systems in the UK, France's Thomson-CSF DETEXIS and the German arm of the European Aeronautic, Defence and Space (EADS) Company and has the eventual goal of developing an operational radar for retrofit aboard combat aircraft such as the Eurofighter, Rafale and Mirage 2000. The Phase 2A element of the effort has involved completion of the design specification and procurement/production of the main subsystems for the CAR demonstrator. CAR itself will comprise a fully populated active antenna that incorporates 1000 transceiver modules and which, together with associated exciter, beam control and data acquisition sub-systems, will be used in an extensive series of ground-based and airborne trials. Elsewhere in Europe, Sweden's Ericsson Microwave Systems is known to have been working on an active electronically scanned array for potential back fit into existing radars such as the company's PS-05/A airborne fire-control set.
Philips Launches New Generation RF Synthesiser Technology
N etherlands contractor Philips Semiconductors has launched a new range of Sigma-Delta Fractional-N RF synthesiser devices that are aimed at high bandwidth, digital radio applications such as cellular telephones, cordless telephone handsets, pagers and cellular base stations. Forming part of the company's 8-family, the new devices have extremely low phase noise values (103 dBc/Hz with a velocity-controlled oscillator centre frequency of 950 MHz and a phase detector frequency of 20 MHz) and the ability to operate at up to 2.5 GHz. The new chips feature a main divider (with integer ratios from 33 to 509) which, in conjunction with a second order, programmable, sigma-delta modulator, provides a frequency resolution of 1/223 times the phase detector frequency. Phase detection functions with input frequencies of up to 30 MHz are available and the devices are further noted as featuring multiple, integrated charge pumps and an auxiliary integer divider that operates within the 80 to 750 MHz range. Device packaging takes the form of a 4 * 4 mm, 24-pin enclosure.
Astor Radar to Begin Trials During 2001
F light trials of a representative prototype of the radar sensor to be used in the UK's Airborne Stand-Off Radar (ASTOR) surveillance system are scheduled to begin during the early part of next year. Based on the American Advanced Synthetic Aperture Radar System (ASARS) -2 equipment, the described flight trials follow-on from completed risk reduction activities that have included extensive wind tunnel testing of models of the sensor's radome. As currently scheduled, a preliminary design review of the ASTOR system will take place during March 2001, with a Critical Design Review (CDR) being undertaken during the following November, at which time, the system design will be frozen. It is expected that airframe testing of the Global Express-based ASTOR platform would have been completed by CDR. Here, the effort will involve US contractor Raytheon (the ASTOR prime contractor), Canadian company Bombardier (airframe supplier), the UK's Defence Evaluation and Research Agency and the UK's Ministry of Defence. In the wake of the service's experience with the introduction of the C-130J transport aircraft, sources suggest that the Royal Air Force (one of ASTOR's two operating services) is extremely keen to maximise its involvement in the planned platform test programme.
Siemens Demonstrates 7 Tbps Fibre-optic
S iemens' Munich, Germany-based Advanced Optical Networks Laboratory has demonstrated the transmission of data over a single fibre-optic at a speed of 7.04 Tbps using Dense Wavelength Division Multiplexing (DWDM) technology. In more detail, the demonstration involved simultaneously transmitting 176.40 Gbps, error-free channels over a 50 km fibre-optic cable. Each 40 Gbps channel was produced by electronic time division multiplexing using a prototype of Siemens proprietary TransXpress FOX multiplexer/regenerator. Use of a special bi-directional transmission system facilitated 50 GHz channel spacing with 0.8 bps per Hz bandwidth spectral efficiency (claimed as a world record in the field of 40 Gbps transmission). With regard to DWDM itself, Siemens notes the technology is used to simultaneously transmit signals that enter the fibre-optic at slightly different wavelengths/carrier frequencies. Each signal is given a colour and is optically divided at the reception point using the same principle as that used to separate sunlight with a prism. Siemens further notes that the DWDM approach allows the parallel transmission of signals with differing data formats and protocols.
Swedish Army to Experiment with Software Radio
S weden's military procurement arm (the FMV) has awarded German contractor Rohde & Schwarz a contract covering the supply of a quantity of M3TR software radios for use in a tactical radio communications environment demonstration. Here, the radios will be used to create and evaluate a tactical net that will be capable of voice and data communications, tactical Internet functions and be compatible with a series of incrementally implemented subsystems. The main aim of the programme is to provide a basis for a procurement effort during the first half of 2002 that will provide a digitised communications capability for the Swedish Army at battalion level. Operating within the 1.5 to 512 MHz frequency range, M3TR is reported as being available in two variants (the 20 W, 1.5 to 108 MHz MR 3000H and the 10 to 50 W, 25 to 512 MHz MR 3000U) and as offering data rates of 5.4 kbps (9.6 kbps planned) at High Frequency and 64 kbps or higher at Very/Ultra High Frequency. The system incorporates provision for a wide range of military and civil waveforms and is noted as being able to function as a packet or trunked radio, a relay, a radio access point or a gateway for a local or wide area network in addition to its baseline terrestrial combat net radio role.
SES ASTRA 2B Successfully Launched
T he Société Européene des Satellites (SES) ASTRA 2B digital broadcast satellite was successfully launched into a geostationary orbit at 28.2º East on 14 September. Co-located with the organisation's ASTRA 2A vehicle, the combination of the two satellites provides SES with 56 transponders operating in the 11.7 to 12.75 GHz frequency bands. Based on ASTRIUM's Eurostar 2000+ bus design, ASTRA 2B has a launch mass of 3300 kg and is equipped with a 32 m solar array. The vehicle has a design life of 15 years and is equipped with 30.109 W output transponders that offer a pan-European footprint or coverage of any part of the earth's surface that is visible from 28.2° East when using the satellite's steerable antenna array. Here, the maximum number of useable transponders is 16. ASTRA 2B is further noted as having 26 and 33 MHz channel bandwidths, a payload power of 6000 W and as incorporating a Gregorian emission antenna. *
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