A Wideband Circularly Polarized Conical-Beam Patch Antenna

Abstract

A circularly polarized conical-beam patch antenna that employs a hybrid feeding mechanism for wideband operation is presented in this paper. It is implemented through using a pair of L-probes and apertures, which are connected by the feeding network, to excite the circular patch in orthogonal directions. The patch is supported by two plastic posts of 0.084 lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> height in the air, where lambda <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</sub> is the free-space wavelength at 2.53 GHz. This antenna possesses an impedance bandwidth of 28.2% (SWR<1.5) and an axial ratio bandwidth (AR<3 dB) of 28.3%. Also, it has left-hand circularly polarized conical patterns with the peaks located at around thetas=plusmn33deg over these bandwidths. Moreover, its 3-dB gain bandwidth and peak gain are 32.4% and 5.5 dBic, respectively