Design and Analysis of a Compact Triple-Band Fractal Antenna with Parasitic Elements and Meandered Transmission Line with Stub for IoT Applications

This paper demonstrates the design and extensive analysis of a novel, space-efficient compact triple-band fractal antenna with parasitic elements designed for Internet of Things (IoT) applications operating at 3.488 GHz, 4.092 GHz, and 5.036 GHz frequencies with peak return loss values of -34.41 dB, - 28.88 dB, and -21.20 dB, respectively. The antenna features a unique Minkowski fractal geometry for size reduction, a triple-band design while maintaining excellent impedance matching characteristics, and a meandered parasitic patch to enhance performance. A U-shaped microstrip impedance matching network with an open-circuit stub is employed to couple the feed line to the main antenna patch. The parasitic patch elements enhance gain and bandwidth performance across all operating frequency bands. Extensive parametric analysis was conducted using CST Microwave Studio to optimize transmission line lengths, stub positions, and meandered line configurations. The presented antenna demonstrates superior performance with VSWR values of 1.04, 1.07, and 1.19 at the respective resonant frequencies, making it highly suitable for smart city and IoT device integration.