Investigations into lightweight patch element for use in dual- or multi- polarized antenna arrays

Lightweight, low profile patch elements with good polarization properties greatly support development of antenna arrays for systems exploring polarization properties, particularly on the receive side. Shape and arrangement of slot pairs under the patch is of top importance to their polarization properties. Use of thin directional couplers occupying minute areas makes feasible antenna operation with two, three or four specific polarizations. Enhancement of polarization quality may advance a lot with clustering patches into subarrays. At this level, a concept of the sequential rotation of antenna elements and careful choice of phases between their feed ports is responsible for further significant improvement in polarization performance. Among main constraints in multi-polarization antenna arrays is the issue of packaging all needed items together.