volume | PIER Journals

Abstract

This study proposes a printed ultra-wideband (UWB) antenna based on a recursive semi-circular fractal topology. The radiating element is generated via the hierarchical decomposition of a primary semi-circular structure into self-similar conductive and void arc segments. This alternating conductive-void arrangement lengthens the effective current path and excites several closely spaced resonant modes that merge into a single continuous band. The antenna is printed on a Rogers RT/duroid 5880 substrate with a thickness of 0.508 mm, characterized by a relative permittivity of ε_eff = 2.2 and a loss tangent of tanδ = 0.0009, and excited by a 50-Ω microstrip feed line over a notched partial ground plane. Occupying 28 × 30 × 0.508 mm³, corresponding to 0.287λ₀ × 0.307λ₀ × 0.0052λ₀. The design achieves a simulated impedance bandwidth from 3.07 to 13.92 GHz (128% fractional bandwidth), and the measured impedance bandwidth extends from 3.03 to 14.05 GHz (129% fractional bandwidth). The simulated peak realized gain is 5.2 dBi, and the measured peak gain reaches 4.97 dBi. Simulated radiation efficiency above 93.8% across the entire operating band was obtained, and it reaches approximately 98.2% around 8 GHz. The measured radiation patterns show good agreement with simulated results at the investigated frequencies. The experimental validation of the proposed antenna with its thin, low-loss profile supports its potential use in diverse UWB wireless applications and sensing systems.

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Ms. Irsal Djeroud

Dr. Habib Khouni

Dr. Muhammad Inam Abbasi

Dr. Maizatul Alice Meor Said