Ka-band Flexible Koch Fractal Antenna with Defected Ground Structure for 5G Wearable and Conformal Applications

This paper demonstrates a low profile, compact and conformal antenna design for 5
^th
generation (5G) wireless devices. The antenna design incorporates two bandwidth-enhancement techniques of fractal geometry and defected ground structure (DGS). The Koch fractal radiating patch is developed with a DGS coupled coplanar waveguide (CPW) feeding. Highly precise fabrication is performed on a thin Polyethylene Terephthalate (PET) film using the additive manufacturing process of conductive ink-based inkjet printing. The results show that the antenna offers a bandwidth which covers K
_a
-band (26.5-40 GHz) and a peak realised gain of 9.7 dBi at 39.7 GHz. The integrated aperture in the ground improves the directivity by converging the radiation in the axis orthogonal to the antenna's plane. The proposed flexible antenna is well suited for integration in millimetre-wave (MMW) based wearable and conformal wireless devices.