Broadband circularly polarized square-slot antenna

The design of a printed slot antenna with broad circular polarization (CP) bandwidth is presented. The proposed antenna is excited by an L-shaped strip with a taper end, connected in series to a microstrip-line-fed located along the diagonal line of the square-slot. Genetic local search (GLS) algorithm is initially used to determine the dimensions of the proposed antenna with optimum impedance matching and CP bandwidth, follow by employing the commercial software IE3D to simulate the performances of the proposed antenna. The measured results demonstrated a wide 10dB impedance bandwidth of 48% and a broad CP bandwidth of 42%, which in comparison is larger than those of antennas found in the literature.