This paper presents the design and fabrication of a wideband circularly polarized CPW-fed compact diamond-shaped antenna. To enhance the wideband response and axial ratio in the desired frequency band, the geometry of the proposed antenna is modified. The modified antenna consists of one radiating element that includes two slits and one horizontal rectangular stub and an improved ground plane. The suggested wide-band antenna has overall measurements of 25 mm x 28 mm x 1.6 mm. The V-shaped slit generates two orthogonal modes in the proposed antenna to excite circular polarization. The rectangular stub improves the wideband response in 2.35-4.62 GHz. The fabricated prototype antenna demonstrates good consistency between simulation and measured results. The suggested antenna resonates over a 2700 MHz transmission bandwidth between 2.35 and 4.62 GHz, making it a good choice for WLAN and WiMAX applications. The average gain in the wideband is 3.1 dBi. It is shown that our suggested approach is a great choice for developing any wideband microstrip antenna for usage in a variety of wireless communication systems.