Special Systems

All Easat standard products started as special projects, where no existing antenna or system in the Easat standard range met the particular customer needs. Typically, no such product existed from any other world-wide manufacturer, or was too costly, or was simply unavailable for one reason or another.

Today's special product is tomorrow's standard catalogue item. Even when an antenna, tower, or complete sensor system has become a standard product, many customers and applications require a degree of tailoring or modification, perhaps to comply with the end user's site or local regulatory requirements or national policy. This evolution of Easat products is continual and relentless. Easat has a flexible team of project managers, engineers and designers fully able to rapidly and economically create the optimum product to meet the customer requirements. This may be to create a single antenna or system for a unique project, for a small batch, or a complete new product line. However, for a completely new design of conventional antenna products, it is useful to note that design and pre-production costs tend to make batch quantities of less than about three or four more difficult to justify. Easat will always advise on the practicality of a potential new project before any costs are incurred.

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For many new antenna designs Easat does not build prototypes, as the Company has built up a wealth of experience such that prototypes are not necessary. This has been found to be a safe and robust strategy, as all antennas undergo rigorous mechanical, radio and electrical testing before being offered to the customer. Additional testing, for example environmental, may be included. Normally, this testing takes the form of contractual Factory Acceptance Tests. Site Acceptance Tests will also be appropriate where Easat is supplying a complete system.

Examples of new antennas which were recently created as Special Products but which are now considered standard catalogue items include:

Lightweight Transportable S band dual beam Air Surveillance reflector;
Radar antennas for military use;
Re-locatable S band dual beam Air Surveillance reflector radar antennas for semi-permanent location at forward air bases;
S band Air Surveillance radar antennas with built in IFF arrays;
Naval X band dual beam radar antennas for optimised sea surveillance and air surveillance coverage;
Bistatic X band linear phased array antennas for FMCW surface surveillance, mostly for airport Surface Movement Radar/ASDE.

Other Special Products have been built for unusual applications, where repeat projects are not necessarily expected. These have included:

FTS - Flight Termination System, consisting of multiple installations of fixed ground based antennas which combine to provide an array to create a closely defined RF field, to control unmanned test or target drone aircraft. System operates at 400 to 475 MHz to provide flight safety at a coastal range.
Suite of reflector antennas for large Radio Frequency Environmental Generator -REG- installed at a UK MoD test facility, to establish the susceptibility of whole aircraft to high power RF radiation at a range of eight frequencies from 1GHZ at 1MW peak power up to 30GHZ at 250 KW peak power. This remains a unique facility world wide, as it is the only such where it is not necessary to relocate the aircraft several times during testing.
S band Airwatch air surveillance reflector antenna, providing >72° of elevation coverage, thereby providing exceptional air surveillance coverage from sea or ground level, to almost directly overhead, thus reducing the 'zone of silence' to a minimum. Installed at a MoD coastal range.

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It is inevitable that some exciting and innovative projects have been taken to the full detail design or prototype stage before being postponed, or even cancelled. This has most often happened with major defence projects. This has resulted in the development of new antenna techniques providing a reservoir of new technology awaiting the right application. For example, Easat now possesses the basic technology for cutting edge new integrated antenna and sensor systems including both active and passive phased arrays. These may employ scanning using wholly electronic beam steering, or may consist of combined mechanical and electronic beam steering methods. These may involve RF frequencies from IFF/SSR frequencies of around 1 GHz, up to high resolution millimetre wave surveillance typically at 74 or 94 GHz, and any allocated radar frequency in between. Antenna arrays may be conformable, i.e. shaped to fit onto vehicle contours or ship superstructures.

Some examples of Special Products which are innovative and merit worthy but which have not yet been put into production include:

Lightweight man pack antenna systems for secure battlefield radio communications;
Compact vehicle mounted IFF phased array transponders for battlefield application (for armoured or un-armoured vehicles);
Log periodic wide band antenna for special applications in communications surveillance;
Antenna Rotators for special horn antennas to search for residual background space RF radiation from the 'Big Bang' origin of universe. Antenna rotates at 60 revolutions/min and involves cooling of waveguide and detector to ultra low temperatures very close to absolute zero.

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Compact bistatic reflector antenna, i.e. having two reflectors, for high resolution microwave radar operating at 74 GHz. For high resolution perimeter or area surveillance at sea or on land; e.g to detect debris on runways, submarine periscopes in harbour areas, or intruders.
Detailed feasibility study for options of active or passive phased arrays for innovative IFF/SSR radar, for a large aircraft carrier. Design brief included high gain from relatively small array dimensions, and close control of unwanted RF radiation outside desired beam shape to minimise sea clutter problems, and to minimise interference with other RF ship systems. If built, antenna system would be in advance of any other currently existing.
C band Naval fire control radar with option of mechanical sector scan, as a less costly alternative to current phased array options.
S band phased array antenna for air surveillance, having active phased array vertical coverage, and mechanical azimuth rotation.

The above examples are intended to illustrate the wide range of Easat experience and skills. Easat will be happy to discuss any antenna or radar sensor concept, and advise on its practicality and possible cost.