A novel compact dual-band microstrip patch antenna achieving high gain and enhanced cross-polarization discrimination for IoT devices and next-generation wireless systems

The escalating demand for high-performance antennas in advanced wireless systems, driven by the rapid increase of 4G/5G networks, IoT, smart cities, and automated vehicles, presents significant design challenges. Existing antenna designs often struggle to balance compactness, dual-band operation, high gain, and crucial Cross-Polarization Discrimination (XPD), which is vital for efficient Multiple-Input Multiple-Output (MIMO) systems. This paper introduces a novel compact dual-band microstrip parasitic circular patch antenna engineered to overcome these limitations. The proposed antenna, featuring a unique “flower-shaped” radiating element and utilizing a low-loss Rogers RO3003™ substrate, achieves stable dual-band operation at 2.62 GHz and 3.91 GHz. Through careful simulation and optimization, including a parametric study of substrate height, the design demonstrates excellent performance reflection coefficients (S11) of -16.9 dB and -17.7 dB, VSWR values well below 2 (1.6 and 1.48), and high total gains of 5.93 dBi and 6.8 dBi at the respective bands. Crucially, the antenna exhibits outstanding XPD values of 35.44 dB at 2.62 GHz and 22.21 dB at 3.91 GHz, ensuring superior polarization purity. The findings confirm that the strategic integration of parasitic elements, optimized material selection, and precise geometry results in an antenna highly suitable for compact and reliable 4G/5G and IoT wireless communication systems, offering enhanced data capacity and reduced interference.