Abstract—This research introduces a planar trapezoidal-shaped antenna for dual-band wireless communications. An inverted L-Shaped Strip (ILSS) is incorporated into the radiating structure with a 50-Ohm Coplanar Waveguide (CPW) feed on a single-layer FR4 substrate to generate dual resonant modes within a footprint (70 mm × 70 mm). The proposed design achieves impedance bandwidths of 1.86 GHz to 3.57 GHz and 7.12 GHz to 8.97 GHz (|S₁₁| ≤ −10 dB), covering the 2.4 GHz WLAN band and the X-Band for Fixed-Satellite Service (FSS) applications. The dual-band behavior is attributed to the coupling between the modified trapezoidal patch and the ILSS, which introduces an additional current path and enhances impedance matching across both bands. It exhibits maximum gains of 2.72 dBi for the lower band and 3.8 dBi for the higher band, along with radiation efficiencies of up to 94.35% and 71.13%. Antenna performance was optimized using the electromagnetic microwave simulation tool Computer Simulation Technology (CST) and subsequently validated through the fabrication and measurement of a prototype, with good agreement and minor discrepancies between simulated and measured results. These findings confirm the antenna’s suitability for Wireless Local Area Network (WLAN) 2.4 GHz applications and uplink/downlink X-band 7.825 GHz FSS applications. Furthermore, the 7.1 GHz to 8.4 GHz range emerges as a promising candidate for future wireless technologies, particularly 6G, due to its inherent capacity for high data rates, increased capacity, and advanced antenna implementations.

Index Terms—dual-band antenna, fixed-satellite service, modified-trapezoidal patch, omnidirectional antenna, patch antenna, Wireless Local Area Network (WLAN) 2.4 GHz

Cite: Suthasinee Lamultree, Punyawat Wiyanat, Kanit Butdaengnoi, and Chuwong Phongcharoenpanich, "Dual-band Modified Trapezoidal Antenna for Wireless Local Area Network (WLAN) and X-Band Communications," International Journal of Electrical and Electronic Engineering & Telecommunications, vol. 15, no. 4, pp. 255-266, 2026. doi: 10.18178/ijeetc.15.4.255-266

Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).