A monopulse antenna composed of corner reflectors was designed, fabricated, and measured. The antenna consists of two corner reflector antennas: The first is used for the sum pattern and the second is used for the difference pattern. The corner reflectors for the sum pattern antenna are made of two sheets of metallic plates arranged orthogonally to each other. Replacing one sheet of the corner reflector of the sum antenna with an artificial magnetic conductor (AMC) sheet transforms it into an antenna for the difference pattern. This proposed antenna design realizes a monopulse antenna system that does not require a complex multiple mode excitation network and phasing circuitry. The experimental results reveal that the peak gain of the difference antenna was 10.6 dBi, the null depth of the difference antenna was lower than-25 dB, the field of view was approximately 22°, and the side lobe level was approximately-13 dB at 2.6 GHz. With the achieved specifications, this antenna system has considerable potential in target localization and angle tracking applications.