A smart antenna is a multiple element antenna system that can control its main radiation pattern direction and shape. This can be achieved by using a fully active system in which each antenna element is controlled independently of one another. This technique requires RF control for each antenna, which introduces high complexity and cost. ERA has pioneered lower cost solutions that only requires a single active element, therefore reducing the complexity and cost.

A smart antenna can improve the quality of a wireless link by providing interference suppression and/or range enhancement as shown below. The potential benefits from using smart antennas, for example, in a wireless system, are improved capacity, higher data rates and better spectrum efficiency. There are also other potential applications where smart antennas can be applied; these include WIMAX and mobile signal detection.

SMART systems rely on the interaction of closely spaced antennas to produce radiation pattern peaks or nulls in a desired direction. Antennas operating in close proximity have inherently different characteristics to an isolated element. Therefore the design of these systems is more challenging. ERA has developed techniques to efficiently analyse multi-antenna systems and the interaction with the RF control circuitry. ERA has demonstrated the design concept by building a prototype dual band WLAN system.

Conventional SMART arrays are band limited by the spatial (or electrical) separation of the elements, since these systems rely on high levels of mutual coupling for pattern formation. ERA has developed an array that can provide pattern adaptation over extremely wide bandwidths, using novel antenna and switching techniques. This system has been operated over a 3:1 bandwidth.

Many future applications will benefit from this type of technology due to improved interference suppression and/or range enhancement, and it is envisaged that multi-antenna systems will have an increasingly important role in future wireless communication systems.