A broadband circularly polarized patch antenna is proposed for WLAN system application. Seven identical curved branches extended from the circular patch are designed to generate circular polarization. Simultaneously, seven identical slots are symmetrically etched on the junction of each curved branch and the circular patch. The dimension of the antenna is reduced by 17.8% compared with no slots. The proposed antenna can produce a 10 dB impedance bandwidth of nearly 21% (2.30–2.85 GHz), a 3-dB axial-ratio bandwidth of nearly 19% (2.34–2.82 GHz) to cover 2.4 GHz WLAN band. The antenna also has the advantages of compact dimension and easy feeding structure.