A compact wide beam circularly polarized antenna

A novel circularly-polarized antenna with wide bandwidth and beamwidth is presented. The antenna is composed of four compact linearly-polarized elements, which are sequentially rotated with a phase difference of 90° and fed by a four-way microstrip feed network. The antenna achieves an impedance bandwidth (S
₁₁
<;-10dB) of 18%, with the HP (Half-Power) and 3dB-AR (Axial Ratio)-beamwidth of about 120° and stable gains of about 4dBi.