An innovative in-body adjustable triple-band Notch UWB monopole antenna with improved bandwidth performance

Abstract

This study introduces a compact ultra-wideband (UWB) monopole antenna featuring adjustable multi-band rejection capabilities while considering the influence of a human body model on stop bands to optimize bandwidth performance. By incorporating two L-shaped slots into the ground plane, the antenna achieves an extensive bandwidth of up to 140% (3–17 GHz). The adjustable triple-band rejection at 4.3 GHz, 5.6 GHz, and 6.5 GHz is realized through the integration of two PIN diodes within a modified W-shaped slit, two Γ-shaped slits with PIN diodes on the radiating patch, and a T-shaped stub on the ground plane. With its compact dimensions (18 mm × 12 mm × 0.8 mm), the antenna provides broad impedance bandwidth, cost-efficient fabrication, suitability for in-body microwave applications, and omnidirectional radiation characteristics in the H-plane. The prototype’s performance is evaluated based on VSWR and radiation pattern analysis, demonstrating that the proposed adjustable antenna is well-suited for various UWB applications. © The Author(s) 2025.