A small rectangular microstrip antenna operated around 5.8 GHz was designed and numerically investigated for sub-6 GHz wireless communications. To facilitate a clear design procedure, this work is divided into three steps. In the first step is a basic patch antenna, in the second step is a rectangular-slotted patch antenna, which enhances both effective current path length and impedance bandwidth and finally in the third Step is a slotted patch antenna, which has been optimized using a genetic algorithm. The optimization was performed by simulation in CST Microwave Studio to find the combinations of the slot width and slot length, slot position, patch dimensions, and partial ground length that yield highest fitness function value. This fitness function combines performance criteria such as resonant frequency error, reflection coefficient, impedance bandwidth, and radiation performance. The optimized antenna has small size of 15×30×1.6 mm³ and resonates at 5.795 GHz with low return loss, large operating bandwidth, and increased back radiation gain. The results show enhancements compared to a basic patch antenna of size 20×40×1.6 mm³.
Nejjari et al. (2026) studied this question.