METHODS TO EXCITE CIRCULARLY POLARIZED WAVES FOR A QUAD-UNIT

摘要

In this article, techniques to generate circularly polarized waves for a quad-unit are investigated. The quad-unit is offset-fed by an open rectangular ring. It has been shown that both 3-dB axial ratio and 10-dB return loss bandwidths can be achieved up to 11%. With a large ring, we have a stable maximum beam at the bore-sight direction. In experiments, it can provide a gain of 7 dBic at 5.5 GHz.