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

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
$\Omega /\square$
, and conductivity of
$\text{0.37}\times \text{10}^5$
 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
$_{02}$
and TM
$_{20}$
modes, whereas through Port-2 three TM
$_{10}$
, TM
$_{02}$
, and TM
$_{20}$
modes are excited. Thereafter, the Co- and Cross-Polarization (CP-XP) isolation of each band is investigated identifying only two useful frequency bands TM
$_{10}$
, 2.9 GHz, and TM
$_{20}$
, 6 GHz. A defected ground structure (DGS) technique is deployed to improve the CP-XP isolation of TM
$_{m0}$
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.