Frequency Selective Surface-Based Dual-Band Dual-Polarized High-Gain Antenna

This article presents a frequency selective surface (FSS)-based dual-band dual-polarized antenna with compact size and high gain. The proposed dual-band antenna consists of a low-band (LB) and high-band (HB) antenna elements. The HB element is coaxially located under the radiator of the LB element, minimizing the overall size. The proposed LB element consists of a two-layer-FSS-based radiator (FSS-radiator) and two pairs of differential feeding probes. Besides, the passband of the proposed FSS-radiator is designed to cover the operating band of the HB element. As a result, the radiation of the HB element can transmit through the FSS-radiator of the LB element. Without reducing HB element gain, instead, the average HB element gain can be improved more than 1 dB by the feeding probes of the LB element. For demonstration, a prototype of the dual-band antenna operating in the LB of 2.3–2.7 GHz and the HB of 3.3–3.8 GHz is fabricated and measured. The dual-band prototype features high gain (~9.1 dBi in the LB and ~8.6 dBi in the HB) in a compact radiation aperture of
$0.32\lambda _{lc} \times 0.32\lambda _{lc}$
or
$0.45\lambda _{hc} \times 0.45\lambda _{hc}$
(where
$\lambda _{lc}$
and
$\lambda _{hc}$
, respectively, denote the guided wavelengths at the central operating frequencies in LB and HB). Moreover, easy fabrication and low cost are achieved. These merits make the proposed antenna suitable for multiband aperture-shared array.