International Report

Denmark Orders Arthur WLS
The Danish Army has awarded Swedish contractor Ericsson Microwave Systems a $40 M contract covering the supply of an undisclosed number of Arthur weapon locating systems (WLS). Based around a G-/H-band (4 to 8 GHz) radar equipped with a phased-array antenna, the Arthur WLS is a one-vehicle system that can detect targets with cross sections down to 10 to 5 cm at ranges of up to 15 km. The system detects, locates and classifies artillery, rocket and mortar threats automatically and carries out threat assessments based on weapon location and/or impact points. Deliveries to Denmark are scheduled to commence in 2000.

Thomson Addresses RWR Range Accuracy
French contractor Thomson-CSF Radars & Contre-Mesures has addressed the problem of determining threat range accurately through the New Generation-Distance (NG-D) model, a new variant of its Serval radar warning receiver (RWR). Covering the E- through J-band frequency range, the Serval RWR is a channelised, crystal video equipment that is a standard installation on French and most export Mirage 2000 combat aircraft. The baseline system estimates threat range from the power level of the received signal. In the Serval NG-D system, newly developed software algorithms are used to establish micro-variations in received parameters from which accurate range data can be derived. The required algorithms have already been demonstrated.

Anglo-Russian Radar Test Programme Revealed
An ongoing Anglo-Russian test programme has been discovered that is evaluating a Russian-developed, high power, short-pulse radar as a potential means of detecting small, fast-moving targets traveling just above the sea’s surface. The programme can be traced back to a 1985 Russian experiment with a high powered 10 GHz system. While funding and logistic problems apparently have curtailed this effort severely, proof-of-concept has been obtained. In early 1993, the UK awarded the Russian Academy of Sciences a contract to design and build a second, improved system for delivery to the UK as an experimental testbed. With UK contractor GEC-Marconi acting as project manager, this new equipment was delivered to a Russian test site during May 1995 and subjected to commissioning and safety checks and initial trials against static targets. Delivery to the UK took place during the autumn of 1995. Between January and March 1996, the equipment was re-assembled by an Anglo-Russian team at a UK Defence Evaluation and Research Agency coastal test site near Portsmouth, UK. Formal acceptance of the equipment took place in May 1996. In September 1996, an additional contract was awarded to the Russians covering the first phase of a planned system upgrade that is scheduled for completion in April.

As supplied to the UK, the experimental radar provides high range resolution and adequate detection energy via 5 ns pulses at a peak power of 500 MW. The equipment utilises a 10 GHz backward-wave oscillator as a transmitter and operates at a pulse repetition frequency of 150 Hz. Incoherent detection is used with clutter suppression being by means of overperiod subtraction (thereby avoiding Doppler aliasing). A wide transmitter bandwidth reduces the range cell and resolves the principle scattering centres of targets. This approach both reduces clutter and obviates target fading. Target detection is a function of the total on-target energy (the product of peak power, pulse duration and the number of pulses). According to GEC-Marconi, a 50 kW transmitter, 40 ms pulse, 250 MHz frequency excursion within the pulse and a 10,000:1 pulse compression ratio would be required for a pulse-compressed radar to emulate the experimental system’s performance.

To date, the described experimental equipment has emitted over 40 million pulses with powers in excess of 300 MW and has demonstrated a high level of reliability. The noted upgrade programme is expected to concentrate on finding an alternative to the low temperature superconducting magnet used currently in the system’s microwave generator, improving cathode structure and providing a radar beam that is agile in direction.

Russians Launch Anti-bugging Radar
The Moscow-based Central Research Institute of Radio and Electronic Systems (TsNIIRES JSC) has developed RASCAN-1, a unique, hand-held sounding radar designed to detect objects (such as bugs), cavities and failures within the structures of buildings. The RASCAN-1 device operates in the UHF (300 MHz to 1 GHz) band and images the responses from elements within a structure that have different permittivity values from those of the complete environment. The equipment comprises two electronics units, an IBM-compatible PC and a hand-held sensing head that incorporates both transmission and reception elements. Sensory images are generated via an automatic interface with the PC’s printer port. System weight is 3.5 kg and maximum detection depth is 0.2 m. Object resolution is 2 to 3 cm, and the equipment can cover a surface area of 4 to 6 m2 in one hour.

TsNIIRES JSC has published test results based on scans of a representative wall section (comprising seven 1 x 1.2 m2 layers of plasterboard with a total depth of 10.5 cm), a ferro-concrete structure and a rubble cored wall faced in concrete. Photographs of the images generated clearly show a range of items (a pair of metal wires; five 25 mm (dia) coins; a mock-up of a pistol; and a 1.5-cm-deep, 3 x 3 cm2 aperture located 1.5 cm in from the section’s outer surface) embedded in the test section, reinforcing bars within the ferro-concrete structure, and individual pieces of rubble and gaps within the faced wall.

Philips Develops Flexible Plastic IC Technology
Netherlands contractor Philips Semiconductors is working on the development of ICs in which polymers replace silicon and that will be suitable for applications such as contactless, readable bar code labels. Apparently, the new technology will allow the reading of codes even when the label is sharply bent. Philips notes that it has confirmed the all-polymer approach by producing prototypes of a complete RF identification tag with a programmable code generator and anti-theft sticker. While semiconducting polymers have been used previously in the active components of metal insulated semiconductor FETs, this current work is reportedly the first time that polymer conductive and insulating components have been used in a transistor.

The substrate used in these prototype devices is a polyimide foil with a conducting polyaniline layer containing a photoinitiator. This layer is exposed to masked, deep ultraviolet light to create the shaping of interconnects and electrodes. The process reduces the conducting polyaniline to nonconducting leucomeraldine, thereby circumventing the need for planarisation of the layers. A 50 nm semiconducting layer of polythienylenevinylene is then applied by spin coating and is converted (at an elevated temperature) using a catalyst. A polyvinylphenol spin-coated layer is used as a gate dielectric and is insulated from the second layer of interconnect (created in the top polyaniline layer using a second mask). Vertical interconnects (for linking transistors in logic circuits) are created by punching through overlapping contact pads in the bottom and top layers (using a mask as a guide). Stack integrity is ensured and the process does not imply a temperature hierachy. Logic functionality comprises a programmable code generator that produces a data stream of 15 bits at 30 bps. The generator used is a 27 mm2, 326-transistor, 300-vertical-interconnect circuit with an onboard clock and has been combined with a proprietary anti-theft device to enable the label to be interrogated from a distance. Philips stresses that this concept relates to ongoing research rather than a new product or technology and expects to be able to improve it with additional work.