A Wideband and Dual-Polarized Millimeter-Wave Antenna With Single-Layered Geometry and Low Profile

This communication reports the design of a novel wideband and dual-polarized millimeter-wave antenna with single-layered geometry and low profile. The antenna is mainly composed of a square patch and two inverted-F antennas (IFAs), and they are located in the same substrate layer. Wide bandwidth has been achieved by taking advantage of the dual resonances generated by patch and IFA modes. The antenna feed is constructed by a through pin connecting to the corresponding IFA and, therefore, leads to a dual-polarized antenna performance as well as a single-layered antenna structure with a low profile of
$0.07\lambda _{0}$
. An L-shaped metal strip has been introduced in order to improve port isolation. The design concept has been verified by prototyping and testing a
$2\times2$
array antenna in the Ka-band. It has been demonstrated that the proposed
$2\times2$
array antenna has a 21% bandwidth with average total efficiency higher than 72% and realized gain of up to 11.1 dBi.