Abstract—This research investigates a compact Asymmetric Coplanar Strip (ACS) fed monopole antenna that generates three frequency bands in wireless communication applications. The antenna design combines the ACS-fed technique with C-shaped, inverted L and U-shaped radiating strip branches to downsize the antenna size and generate multi-band radiation. The antenna is implemented on an inexpensive FR-4 substrate measuring 20×9×1.6 mm3. A systematic parametric assessment that includes variations in the length and width of the radiating strip has been carefully carried out, identifying three optimal frequency operational modes for the proposed antenna using an EM simulator Ansoft HFSS. The impedance bandwidths of the lower, middle, and higher frequency modes are 320 MHz (2.31-2.63 GHz), 470 MHz (3.3-3.77 GHz), and 2820 MHz (5.12-7.94 GHz), respectively. At 2.5 GHz, 3.55 GHz, and 5.45 GHz resonant frequencies, the measured antenna gain parameters are 5.67 dBi, 5.21 dBi, and 4.56 dBi. Due to its compact form factor and stable characteristics, the proposed antenna design emerges as a promising solution for internal antenna implementation in the Internet of Things (IoT) devices, especially in the context of wireless local area networks (WLAN), worldwide interoperability for microwave access (WiMAX), 5G sub-6GHz, and vehicle-to-everything (V2X) applications.