Design and Evaluation of L-T Slot Flower-Shaped Microstrip Antenna For IoT Applications

Microstrip patch antennas encounter constraints in both bandwidth and gain, restricting their adaptability across diverse frequency ranges and impeding their effectiveness in achieving higher signal strength for long-distance communication. We design a multiband microstrip patch antenna with a unique three-petalled flower shape. The printed monopole antenna incorporates a micro-strip feed line excited by a defective ground plane, optimized through Finite Element Method (FEM) simulation. This optimization results in three distinct multiband frequencies (2.29GHz to 2.51GHz), (3.20GHz to 3.75GHz), and (4.20GHz to 5.99GHz), which significantly improves impedance matching. The introduction of L-T slots to the patch improves radiation efficiency, increasing from 88.78% to 90.71% at 3.25 GHz and from 88.32% to 88.61% at 5.5 GHz. The antenna has an omnidirectional radiation pattern and a maximum gain of 3.64 dBi, which makes it appropriate for Wi-Max and WLAN-based Internet of Things applications.