Mutual coupling reduction is required to miniaturize wireless devices in many applications. The mantle cloak technique has been studied to reduce mutual coupling. This paper proposes a square rod mantle cloak antenna with a low-frequency rejection band. The rejection band is 720 MHz and the operation band is 750 MHz. The proposed antenna structure contains a copper rod-covered dielectric substrate with strip conductors at the center of each face. The proposed antenna was validated by comparing the simulation and measurement results.