A New Approach to Design Circularly Polarized Beam-Steering Antenna Arrays Without Phase Shift Circuits.

A new approach to generate beam steering for the circularly polarized (CP) antenna array without phase shift circuits is proposed. The proposed approach is a low cost one compared with those with phase shifters. It is found that in spherical coordinate system ( $r$ , \theta $ , and \varphi $ ), for any constant r$ and \theta $ , as \varphi $ varies from 0 to 2\pi $ , the phase of the CP antenna’s copolarized far field will progress linearly by 2\pi $ , and the magnitude is constant. If a CP antenna is rotated around its own phase center by certain degrees, there is a phase difference between the copolarized electric far fields generated by the antenna before and after rotation. An N \times N , 45°, and 90°, the mainlobe can be scanned from −25° to +24°, −36° to +35°, and −24° to +25°, respectively. [ABSTRACT FROM PUBLISHER]