An antenna array includes two acutely bent dipole antenna elements placed back-to-back on a printed circuit board with integrated micro-strip balun transformers which a Wilkinson divider drives 180 degrees out of phase. In an embodiment, the antenna array sits on a vertical blade support structure to...http://www.google.de/patents/US6249260?utm_source=gb-gplus-sharePatent US6249260 - T-top antenna for omni-directional horizontally-polarized operation
