Article

BlightER on the battlefield

Electronics Weekly, Military and Aerospace special feature, 23 July 2003

Plextek is currently developing a low cost electronic-scan radar for rapid deployment in the field called Blighter - Battlefield Light-weight E-scan Radar. Plextek's experience in both the Telecommunications and Defence market sectors has allowed it to bring significant advantages, especially cost, to the design of this portable radar system. The design emphasis has focused on the capability that the radar can offer given standard system components rather than trying to design custom system components to achieve a certain performance. The radar will perform as well as it can - and given the low cost of the system components, there are lots of dBs to the £. For those users who need more dBs, then the £s can be modified to match.

Conventional phased-array radars have elaborate and expensive active antenna structures to provide electronic beam steering. Using knowledge gained from the latest mobile telephone base station designs, the Blighter antenna is a complex to design, yet cheap to manufacture, printed antenna structure. The lack of active components allows antennas to be fabricated without the need for complex calibration functions. The simplicity also improves reliability and robustness.

Perhaps the most novel feature of Blighter is the way in which modern commercial handheld products and web-enabling technology is integrated into the product. The Blighter base unit contains almost a complete radar - Antenna, Tx, Rx, synthesiser, mixers, signal and data processing, power supply and a wireless data link. To provide the external user interface, the Blighter base unit hosts a web server with live processed radar information and control dialogue. This is linked by wireless, IEEE802.11, to standard commercial laptops and PDAs (Personal Digital Assistant).

The PDA or laptop simply uses its in-built web browser to view the 'web page'. In practice, an application is downloaded via the internet link from the Blighter base unit to offer the appropriate interface for the particular handheld unit. Multiple users can view the radar or other sensor data, with authorised users having control of radar modes and active search sectors. The static electronic scan antenna offers great flexibility for optimising the radar mode for individual sectors and for allowing power management by snoozing between scans.

Although Blighter's primary function is radar, other sensors can be included in or attached to the base unit to provide the users with greater situational awareness. An excellent example is the inclusion of a video camera to verify or confirm the detections being made on the radar. As a standard low-cost sensor the ubiquitous web cam is an obvious candidate, and for users requiring better resolution or night-time sensitivity, then alternative, more costly sensors could be included.

Plextek is currently developing a demonstrator to integrate the techniques discussed above. The Blighter base unit with its printed antenna structure will be operating at the Plextek site near Cambridge. This will serve a web page carrying live radar and streaming video available via the internet and ultimately on PDAs and Laptops via IEEE802.11. Plextek will be showcasing Blighter at DSEI in September.

In summary, by using commercial techniques and components, highly capable and cost-effective systems can be developed in months. Availability of, and familiarity with, commercial PDAs and laptops allows users to be able to use the equipment with ease, while wireless connectivity coupled with web based data presentation enables standard application software and interfaces to be used without modification.

Written by Mark Radford