Design of Switchable Dual-Axis Monopulse Array Antenna With Wide Beam-Steering Functionality Employing Tri-State SPDT Switches

This paper presents a switchable dual-axis monopulse antenna with wide beam-steering functionality. The proposed antenna consists of four linearly polarized microstrip antennas, a magic-T, a phase-shift-keying (PSK) modulator, and two tri-state single-pole double-throw (SPDT) switches. The SPDT switches control the beam steering in three different conditions. According to the amplitude ratio of magic-T's two input signals, the phase difference of the patches changes so that the beam tilts. The proposed antenna employs a PSK modulator to achieve a wide range of beam steering among ±20°.