The printed quadrifilar helical antenna (PQHA) represents a very attractive candidate for many applications such as mobile satellite communications,br oadcasting satellite systems or global positioning systems,due to hemispherical radiation, circular polarization,good axial ratio,and low cost. Nevertheless,the bandwidth of a conventional PQHA could be insufficient for such applications. Therefore,in this paper, a technique for increasing the bandwidth of a PQHA by adding a shorted parasitic helix is presented. The new folded printed quadrifilar helical antenna (FPQHA) is designed to achieve 30% of bandwidth in axial-mode. Moreover, due to the printed arms on one substrate face, the FPQHA manufacturing is very simple. Measured results are presented to validate the concept.
