A Detachable Radiator–Feed RHCP Wearable Button Antenna for 5G New Radio

ABSTRACT

This paper presents an experimentally validated compact right‐hand circularly polarized (RHCP) metallic button antenna for garment‐integrated sub‐7GHz 5G New Radio applications. Departing from conventional monolithic button antenna designs with integrated feeding structures, the proposed design introduces a physically decoupled radiator–feed architecture enabling modular and detachable operation. The proposed radiator, realized as a metallic button element, enables seamless integration into garments without altering conventional clothing structures. To demonstrate practical feasibility, prototypes of both the radiator and feed modules are fabricated and characterized under realistic on‐body conditions. The measured S ₁₁ and axial ratio bandwidths exhibit consistent overlap over 6.3–6.9 GHz (9.1%) in a standing posture and 6.4–6.9 GHz (7.5%) in a sitting posture, thereby covering a significant portion of the 5G NR band. The antenna demonstrates stable CP characteristics with peak measured gains exceeding 7.1dBic across the operation band for both postures. Additionally, full‐wave simulations confirm low human exposure levels with a maximum point specific absorption rate (SAR) of 0.552 W/kg and a 1 g averaged SAR of 0.0598 W/kg for an input power of 0.5 W.