In this paper, the design, simulation and measurement of a planar antenna at Ka-band targeted for 5th-generation mobile terminal application are presented. Based on tapered-slot configuration, this antenna exhibited an input return loss of greater than 10 dB covering entire Ka-band from 26.5 GHz to 40 GHz. The measured gain was 5 dBi at 28 GHz and 7.9 dBi at 38 GHz. Gain enhancement was achieved through elliptic-shaped dielectric loading in the direction of radiation. A 2-dB improvement in gain at 28 GHz and 38 GHz was obtained. The proposed antenna configuration can easily be realized using standard printed-circuit-board (PCB) process for the ease of integration with other planar circuitry, suitable for applications of the next generation mobile terminals at millimeter-wave frequencies.