A single-FED slot-aperture hybrid antenna for broadband circular polarization operations

This article presents a microstrip-fed slot-aperture hybrid antenna for wideband circularly polarized (CP) operations. The antenna consists of a U-shaped slot, a rectangular aperture, and a probing strip fed by a microstrip line. In general, the U-shaped slot and the rectangular aperture resonate at two separate frequencies. When properly arranged, the proposed antenna may resonate over a single wideband of CP radiation. The 3-dB axial ratio (AR) bandwidth of the presented antenna in free space is about 27% with the gain level about 34 dBic. When a planar reflector is incorporated for the desirable unidirectional pattern, the presented antenna has an enhanced gain about 7 dBic with a 3-dB AR bandwidth of 25% and a front-to-back ratio of about 14 dB. Good agreement between measured and simulated results was achieved. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:412–415, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26569