Ultra‐thin electromagnetic bandgap backed fractal geometry‐based antenna for 24 GHz ISM band WBAN

A compact, ultra-thin electromagnetic bandgap (EBG) backed antenna is presented for the 24 GHz ISM band WBAN applications. The proposed has Koch fractal geometry-based bow-tie slots, designed with an overall dimension of 0.91 λ 0 ${\lambda }_{\mathbf{0}}$ × 0.84 }_{0}$ 0.01 and by a 5 element thick EBG structure; it fabricated on flexible Rogers 5880 substrate (thickness = 0.127 mm dielectric constant ε r ${\varepsilon }_{r}$ 2.2, tanδ 0.0009). In comparison to previously published K prototype antennas, our more compact form factor. low profile, via-less unit cell structure dimensions 0.254 , possesses both Artificial Magnetic Conductor (AMC) characteristics. It straightforward fabricate at millimeter-scale. performance parameters design are investigated in terms on-body reflection coefficient free-space radiation patterns without structural bending. enhances antenna's front-lobe gain 2.3 dB, decreases back-lobe 12.6 dB specific absorption rate (SAR [1 g]) from >50.9 W/kg <6.14 W/kg, significantly reducing potential harm human body. Experimental investigations revealed high insensitivity body proximity, preserved deformation.