RESEARCH ARTICLE A dual-band semi-circular patch antenna for WiMAX and WiFi-5/6 applications Liton Chandra Paul 1 | Himel Kumar Saha 1 | Tithi Rani 2 | Rezaul Azim 3 | Mohammad Tariqul Islam 4 | Md Samsuzzaman 5 1 Department of Electrical, Electronic and Communication Engineering, Pabna University of Science and Technology, Pabna, Bangladesh 2 Department of Electronics & Telecommunication Engineering, Rajshahi University of Engineering & Technology, Rajshahi, Bangladesh 3 Department of Physics, University of Chittagong, Chittagong, Bangladesh 4 Department of Electrical, Electronic and Systems Engineering, Universiti Kebangsaan Malaysia, Bangi, Malaysia 5 Department of Computer and Communication Engineering, Patuakhali Science and Technology University, Patuakhali, Bangladesh Correspondence Liton Chandra Paul, Department of Electrical, Electronic and Communication Engineering, Pabna University of Science and Technology, Pabna, Bangladesh. Email: litonpaulete@pust.ac.bd Summary A semi-circular patch antenna (SCPA) is designed for WiMAX and WiFi-5/6 communications. The footprint of the proposed SCPA is only 30  40  1.575 mm 3 , which is composed of a semi-circular patch and a partial ground plane. The main strength of this work is that the estimated wide dual-frequency span of 2.39–3.75 GHz and 5.39–7.18 GHz are contributed with two sharp resonances at 2.77 and 6.46 GHz, respectively. The proposed SCPA has been practically tested after fabrication. The measured results confirm that the designed antenna achieved the bandwidth necessity for WiMAX 1.5 (2.5–2.69 GHz), WiMAX 2 (3.4–3.6 GHz), WiFi-5 (5.15–5.85 GHz) and WiFi-6 (5.925–7.125 GHz). In the two resonance frequencies of 2.77 and 6.46 GHz, the designed antenna achieved a gain of 2.558 and 4.109 dB, respectively. In addition, the SCPA also manifests good radiation properties and achieves an average efficiency of more than 90%. A professional version of the 3D elec- tromagnetic simulator is utilized to examine the effect of diffident parameters and model the tested antenna. KEYWORDS semi-circular patch antenna, partial ground plane, WiMAX, WiFi-5/6, CST 1 | INTRODUCTION Wireless technologies are becoming progressive due to the dramatic increase in the demand for cellular internet con- nectivity to billions of wireless device users worldwide. 1 Different modern broadband wireless technologies like Bluetooth (2.4–2.485 GHz), LAN (5.47–5.725 GHz), WiMAX (3.4–3.6 GHz), mobile communication, radar, satellite communication and so forth use different frequency bands of the spectrum to meet the increasing demand of high- speed data transmission. 2–4 According to IEEE standard 802.11ac and 802.11ax, frequency band ranging from 5.925 to7.125 GHz is allocated to WiFi-5, and WiFi-6 is allowed to work at 5.925–7.125 GHz band. Recently, WiFi-6 (802.11ax) has been introduced, providing a peak data transfer speed of up to 9.6 Gb/s. 5 All wireless systems need a low-cost, simple and compact antenna to communicate effectively. 6 Due to low profile, lightweight and compactness features with higher efficiency, microstrip patch antennas have become very popular in current wireless devices. 7 A good number of antennas have already been reported to operate at the 5.925–7.125 GHz band. For example, for WiFi applications, Jianzhong and the rest 8 propose a dual-band miniature slot antenna. In the bottom layer of the designed antenna, there is a slotted radiator fed by an L-shaped microstrip line and resonating at 2.45 and 5.8 GHz. With an overall size of 20  21  1 mm 3 , the antenna achieved dual working bands of 2.42–2.49 GHz and Received: 22 April 2022 Revised: 8 July 2022 Accepted: 20 August 2022 DOI: 10.1002/dac.5357 Int J Commun Syst. 2022;e5357. wileyonlinelibrary.com/journal/dac © 2022 John Wiley & Sons Ltd. 1 of 13 https://doi.org/10.1002/dac.5357