Compact Wideband Antenna at 3.5 GHz for 5G Wireless Applications

Abstract

This paper discusses the creation and testing of a small wideband antenna made for 5G use at 3.5 GHz. The antenna is designed to work in sub-6 GHz frequencies; this range is generally agreed upon as being very important for new fifth-generation wireless communication systems. The antenna was fabricated using FR-4 material with a thickness of 1.6 mm and has an overall compact size of 46 mm × 40 mm, which makes it appropriate for integration into small low-cost devices. Using an FR-4 substrate also has benefits in terms of availability, ease of fabrication, and lower manufacturing costs—all critical factors in practical antenna design. The design process began with the creation of a small conventional micro-strip antenna for 3.5 GHz. At this stage, the first structure was chosen to give a simple efficient radiating element around the required resonant frequency. Then elliptical slots were used to increase the impedance bandwidth by changing current distribution on the radiating patch and better matching impedance between the antenna and feeding structure. After these modifications, the antenna achieved a return loss of −41 dB at the operating frequency and a bandwidth of 934 MHz. These results indicate a clear improvement in performance, especially in resonance stability and broadband behaviour. This compact configuration also supports low-cost fabrication and practical integration into modern wireless devices requiring stable operation in the sub-6 GHz 5G frequency range. Therefore, the proposed antenna effectively covers the globally allocated 3.5 GHz band for 5G applications and can be considered a promising candidate for compact and efficient wideband 5G wireless communication systems.