Beam steering microstrip array antenna with orthogonal excitation

In this paper, a novel beam steering microstrip array antenna is proposed and its characteristics are investigated. The proposed beam steering array antenna consists of four square patches and two orthogonal feed circuits using magic-Ts. The patch elements are excited by two orthogonal modes in time-domain. The phase difference of the elements excitation changes according to the amplitude ratio of input signals. Therefore, the beam steering capability is achieved by changing the amplitude ratio of the input signal. In this paper, the beam steering performance is confirmed by EM simulations and experiments.