Low-Profile Dual-Band Tripolarized Antenna Using Monopolar Slotted Patch
Son Xuat Ta, Thanh Tung Phung, Khac Kiem Nguyen, Nghia Nguyen‐Trong
Abstract
A dual-band multiport antenna with three orthogonal polarizations is proposed for 2.45 and 5.8 GHz bands. It consists of a monopolar slotted patch with shorting vias for vertically polarized omnidirectional radiations and differential-fed stacked patches for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$x$</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">$y$</tex-math></inline-formula> -polarized broadside radiations. To avoid undesired effects among different radiation modes, four shorting vias in the monopolar patch are utilized to feed the stacked patches. The final design with 0.07 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\lambda _{2.45-\text{GHz}}$</tex-math></inline-formula> profile achieves measured 10 dB return loss bandwidths of 50 and 180 MHz at the two target bands, respectively, and an isolation of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\ge$</tex-math></inline-formula> 40 dB among all the ports, showing significant improvement as compared to the existing designs for the same application in the literature. Its radiation characteristics are validated by the far-field measurements, which illustrate highly symmetrical patterns and low cross polarization in all the operation modes.