Analysis of a compact wideband DGS-inspired octagonal patch antenna for sub-6 GHz 5G and IoT wireless systems

Komalavalli Subramanian (Einstein College of Engineering)
Divya Subramani (Dr. N.G.P. Institute of Technology)
Sornalatha Ravindran (M.I.E.T. Engineering College)
Muthu Manickam Anbarasu (Shanmuganathan Engineering College)
Mohan Chinnasamy (St. Joseph’s Institute of Technology)
Anita Daniel (Sri Sai Ram Engineering Colleg)

International Journal of Reconfigurable and Embedded Systems (IJRES)
Vol 15, No 2: July 2026

The proposed compact wideband antenna is developed to meet the increasing demand for efficient and miniaturized radiators in sub-6 GHz fifth generation (5G) and internet of things (IoT) wireless systems. The design features an octagonal radiating patch integrated with modified H-shaped slots to enhance the current path and impedance matching, while a graded defected ground structure (DGS) is introduced to improve bandwidth (BW) and suppress unwanted surface wave effects. Fabricated on an FR4 substrate and energised by a simple stripline feed, the antenna maintains a compact size of 18×15 mm² without compromising performance. It achieves a wide fractional BW of 42.81% spanning 3.1–5.8 GHz, with a resonance centered at 4.6 GHz and obtained reflection coefficient of −36 dB, indicating excellent impedance matching. Additionally, the suggested antenna provides the maximum gain of 3.14 dB and an overall radiation efficiency of 80.5%, demonstrating stable radiation characteristics while making it ideal for small, low-profile 5G and IoT communication devices.