Compact Slotted-Circular Microstrip Patch Antenna for Sub-6 GHz IoT Applications

This paper presents the design and performance analysis of a compact slotted circular microstrip patch antenna for the Internet of Things (IoT) and wireless communication systems operating in the 5 GHz band. The proposed design integrates multiple concentric slots in the circular radiating patch, combined with a partial ground plane and symmetric rectangular slots. This configuration aims to enhance the impedance bandwidth and achieve stable resonant performance at 5 GHz to meet the demands of modern high-frequency applications. The initial design parameters were calculated using standard analytical equations and collectively optimized through full-wave electromagnetic simulations in ANSYS HFSS. The antenna achieves a measured return loss of –26.17 dB and bandwidth of 7.2% (4.82 GHz to 5.18 GHz) and a VSWR of 1.1033, with excellent impedance matching. A peak gain of 4.39 dB with stable omnidirectional radiation patterns validates the effectiveness of the design for Wi-Fi, 5G, and IoT devices. The integration of compact geometry and good radiation properties makes the slotted circular patch antenna a novel proposed design for integration into modern IoT modules and low-power wireless communication systems operating in the 5 GHz spectrum.