To solve the problems of low gain, narrow bandwidth, and poor radiation directivity of conventional ground penetrating radar antenna, this paper proposes an ultra-wideband and high-gain antipodal tapered slot antenna (ATSA) with planar metamaterial lens. As a constituent part of this lens, a new non-resonant metamaterial unit cell is introduced and analyzed by the full-wave simulation tool. The single-layer planar lens composed of the designed unit cells with different sizes is placed in the maximum radiation direction of the ATSA to greatly enhance its radiation capability. The proposed planar lens antenna has a wide impedance bandwidth of 107.4% (2.41–8 GHz) and −3 dB gain bandwidth of 54.5% (4–7 GHz), respectively. The gain increases averagely by 6.0 dB in the whole operating frequency band, and the peck gain reaches 15.4 dBi at 5.5 GHz. And its excellent performance shows a high application prospect in ground penetrating radar and microwave imaging system.
