Design, Fabrication, and Test of a Novel Broadband Dual-Polarized Microstrip Antenna for WLAN Applications

A dual-polarized dual-layer wideband microstrip antenna is presented. Dual orthogonal linear polarization and enhanced isolation between two ports are achieved by employing two radiating patches perpendicular to each other and printed on two separate substrates. Broadband behavior of the antenna is realized by using two wideband double-sided printed strip dipole and angular ring as radiating patches along with wideband baluns as feeding system. The patches are connected to baluns with two separate twin-lead transmission lines. Moreover, to improve the impedance bandwidth of the strip dipole significantly, adiamond-shape parasitic patch is artily incorporated into the top side of the upper layer ofthe antenna. The proposed antenna can easily be employed in large-scale arrays thanks to the feeding system of the patches. A prototype is fabricated to verify the simulation results where the measurement results show the −10 dB impedance bandwidths of 40% (4.3–6.5 GHz) and 43% (4.2–6.5 GHz) at port #1 and port #2, respectively. Besides, the isolation between two ports and the radiation gain are obtained around 35 dB and 9 dBi, respectively, which are useful for WLAN applications.