Series-Fed Dual-Polarized Antenna Arrays for Single-Layer Photolithography Fabrication

This letter proposes a novel method to design series-fed (SF) dual-polarized antenna arrays. The proposed antenna arrays consist of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$nm$</tex-math></inline-formula> radiating elements placed in <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n \times m$</tex-math></inline-formula> grids, where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$n$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$m$</tex-math></inline-formula> are arbitrary odd numbers. The proposed arrays are fed by two probes, each of which is used to excite one of the TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">10</sub> and TM<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">01</sub> modes in the middle patch, and hence, one of two orthogonal linear polarizations. For each polarization, the middle patch operates also as a four-way power divider to distribute the signals that excite this polarization across the array. Both the radiating elements and the feeding network of the antenna array are realized on a single metal layer, which makes the proposed antenna array a low-cost solution. The proposed antenna concept has been verified by the design and measurements of a <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">${\text {3}} \times {\text {3}}$</tex-math></inline-formula> antenna array. The prototype operates over 5.53 GHz to 5.87 GHz frequency range and achieves a maximum gain of 15.8 dBi at 5.84 GHz.