Design of Frequency Reconfigurable Hybrid Fractal Antenna for Wireless Applications

Abstract

The article proposes a novel frequencyreconfigurable hybrid fractal antenna that comprises hybrid fractal geometry (combining Koch and self-affine fractals) integrating with two PIN diodes. The overall size of the antenna is 68 × 𝟑𝟏 × 𝟏. 𝟔 mm3 placed on a FR4 substrate material. It can work in wideband, i.e., L- and S-band, by altering the states of two switches. A partial ground plane is used to achieve a wideband and good radiation performance in the antenna. It has two operational bands. These bands are case I, 1.69–3.62 GHz with 72.7% impedance bandwidth when all diodes are OFF; and case II, 1.48–3.18 GHz with 73% impedance bandwidth when all diodes are ON. As a result, the designed antenna's impedance bandwidth offers continuous wideband frequency covering from 1.48 GHz to 3.62 GHz (84%). The peak realized gain of 2.5 dBi has been attained at 3 GHz in the S-band. The radiating element has stable radiation properties and a Cross-polar Discrimination (XPD) greater than 30 dB, making it appropriate for wireless communication applications