A broadband Fabry-Pérot cavity antenna designed using an improved resonance prediction method

We have proposed a wideband Fabry–Pérot cavity (FPC) base station antenna for wireless broadband Internet (WiBro) service in Korea. To widen the radiation bandwidth of our antenna, unit cells printed on a superstrate have been gradually tapered according to a proposed linear tapering equation. Also, all openings in the lateral directions have been enclosed using four metallic sidewalls to enhance the overall performance of the antenna by reducing unnecessary wave leakage. Furthermore, the radiation aperture has been designed in a rectangular shape to create sharp and sectoral beam shapes in the elevational and azimuthal directions, respectively. For a more accurate determination of the FPC resonance, an improved prediction formula has been used. We have demonstrated the basic principle of bandwidth widening using higher mode behavior, which appears at a higher frequency region by means of tapered cells on the superstrate. In addition, to show the effectiveness of simple tapering of unit cells, we have compared the performance of two antennas covered with the tapered and uniform (nontapered) superstrate. Tapering the unit cells has expanded the fractional radiation bandwidth about four times wider than that of the antenna using uniform unit cells. The measured behaviors of our antenna are in good agreement with the simulated data, which confirms the validity of our design and analysis approach. The measured behaviors of our antenna are in good agreement with the simulated data, which confirms the validity of our design and analysis approach. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:1065–1069, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.25898