Active Electronically Scanned Arrays

Phased array antennas or rather Electronically Scanned Arrays (ESA) have obtained many attentions in recent years thanks to their capability in generating steerable and reconfigurable patterns without rotating the antenna system.

Generally, they are used in many applications like radar, surveillance and communications system.

The design of an ESA is usually a complex engineering task for required performances are conflicting to each other and they are not abele to considered separately.

Our research works is mainly focused on the design of broadband Electronically Scanned Arrays with wide angular ranges and small dimensions. Thus several study on planar antennas has been made in order to check their performances in an ESA.

_{Figure 1 - A single elementt suitable for ESA applications}

Although the majority of analysis are carried out with a commercial electromagnetic software, the development of preliminary design and post-processing tools are also part of our works. In particular, a graphical method for a preliminary design of an ideal phased array antenna has been developed and implemented.

_{Figure 2 - Measurements on the element of Figure 1}

Recently many attention has been given to the analysis of the mutual coupling between elements, which study is going on thorough two ways. The first one focuses on the use of parasitic elements, which have to be directly printed on the antenna. Instead, the idea behind the other is based on an analytic characterization of the mutual coupling in order to enhance the preliminary design tool.

_{Figure 3 - small 2x2 sub-array with parasitic meandered lines to lower mutual coupling}

Figure 4 - Large 8x4 array under S-parameter measurements