ABSTRACT
This chapter discusses a microstrip line-fed ultra-wideband (UWB) antenna having measurements of 20 × 23 × 1.6 mm3 and a patch with an octagonal slot and defected ground structure (DGS) suitable for various wireless communication systems. In order to improve the radiation properties, the suggested design structure includes a square patch with truncated edges, an octagon-shaped slot carved into the metal plane’s canter point, and an open-ended slit etched into the ground plane right below the feed line to produce a wider impedance bandwidth. The designed structure exhibits a wide impedance frequency range of 3.10 to 20.00 GHz (6.45:1), that is, a frequency of 16.9 GHz having a fractional bandwidth (FBW) of 146.32% using affordable FR-4 epoxy as a substrate with relative dielectric constant (εr) of 4.4 and loss tangent (tanδ) of 0.02. At 4.65 GHz, the designed structure displays a return loss of 56.31 dB with a maximum gain of 3.16 dBi, and an 80% radiation efficiency. The proposed design shows a remarkable front-to-back lobe ratio around –10 dB throughout the full ultra-wideband. Experimentally comparing the fabricated design to the simulated data of the final antenna reveals that they are in good agreement.
