A Slender Fabry–Perot Antenna for High-Gain Horizontally Polarized Omnidirectional Radiation

In this communication, a special Fabry-Perot (FP) cavity antenna with a slender structure is proposed to realize an omnidirectional radiation pattern with horizontal polarization. In our design, a partially reflective strip consisting of periodical slots is placed over the aperture of a long and narrow cavity, thus generating an FP resonance with a uniform electric field distribution along this aperture. As the slot arrays are excited in phase and with a nearly identical amplitude, the proposed slender architecture can provide a horizontally polarized omnidirectional radiation pattern with an enhanced directivity. The proposed antenna is prototyped with a length of 2.95λ (λ is the free space wavelength at the center frequency). In well agreement with the simulation results, the experiment verifies that an omnidirectional pattern is achieved over the operating band (2.41-2.5 GHz), with a realized gain of 7.1-8.52 dBi and a gain variation on the E-plane less than 2.3 dB. In virtue of the low-profile all-metal structure, high efficiency (>86%), and enhanced gain, the proposed slender FP antenna is promising for future wireless communication applications.