A Compact Modified Inverted F Antenna with Enhanced Performance for IoT Devices in 2.45 GHz ISM Band

The unprecedented needs and expansion of the Internet of Things (IoT) have increased the demand for compact, highly efficient antennas ensuring reliable connectivity within the 2.45 GHz Industry, Scientific and Medical (ISM) band. A compact and optimized miniaturized modified inverted-F antenna (IFA) for Internet of Things (IoT) applications in the 2.45 GHz ISM band is presented in this study. The proposed antenna uses a parasitic slot and ground-plane changes to obtain a small dimension of 40×25×1.6 mm³ to improve impedance matching, bandwidth and radiation performance. An FR-4 substrate with a dielectric permittivity of 4.4, a substrate thickness of 1.6 mm and an input impedance of 50 ohms are used to design the antenna to guarantee correct matching. With a fractional improved bandwidth of 22.85%, a VSWR of 1.24 and a return loss of -19.16 dB, the antenna operates efficiently at 2.45 GHz. Furthermore, it provides a gain of 1.10 dBi with a radiation efficiency of 71.58% and an omnidirectional radiation pattern suitable for dense IoT environments. The integration of Defective Ground Structure (DGS) and parasitic slotting demonstrates significant performance improvements compared to conventional IFA designs while maintaining a low profile and simple structure. Due to its compact configuration, wide bandwidth, and stable radiation characteristics, the proposed antenna is a promising candidate for miniaturized IoT devices requiring reliable 2.45 GHz connectivity