Multimode-Inspired Low Cross-Polarization Multiband Antenna Fabricated Using Graphene-Based Conductive Ink

Abstract

In this letter, a dual-port antenna for multiband operation is reported. The prototype of the proposed design is fabricated using graphene-based conductive ink printed textile showing the surface resistance of 2.7 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\Omega /\square$</tex-math></inline-formula> , and conductivity of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\text{0.37}\times \text{10}^5$</tex-math></inline-formula> S/m. The microstructural analysis of the conductive ink printed cotton fabric is done by field emission scanning electron microscopy (FESEM) and electric characteristic is extracted using a four-probe measurement. The proposed antenna resonates at a triple-band and dual-band mode through two different feeding locations. Through Port-1, the antenna resonates only at higher order TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{02}$</tex-math></inline-formula> and TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{20}$</tex-math></inline-formula> modes, whereas through Port-2 three TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$_{10}$</tex-math></inline-formula> , TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{02}$ </tex-math></inline-formula> , and TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{20}$</tex-math></inline-formula> modes are excited. Thereafter, the Co- and Cross-Polarization (CP-XP) isolation of each band is investigated identifying only two useful frequency bands TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{10}$</tex-math> </inline-formula> , 2.9 GHz, and TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{20}$</tex-math></inline-formula> , 6 GHz. A defected ground structure (DGS) technique is deployed to improve the CP-XP isolation of TM <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$_{m0}$</tex-math></inline-formula> modes achieving CP-XP isolation better than 30 and 15 dB in both useful bands. The measured results have a fairly good agreement with simulated results.