This paper presents a passive 2-D beam steering solution comprising of a triple-mode circular waveguide horn antenna operating at Ka-band frequency of 30 GHz, a pair of identical dielectric lenses employing Risley prism and a parabolic phase correcting surface. The circular waveguide horn antenna generates TE 11 , TM 01 and TE 21 modes independently. The pair of identical dielectric lenses employing the Risley prism concept are axially rotated individually and/or simultaneously to steer the radiated beam. The parabolic phase correcting structure is used to further improve the performance of the steered patterns. Overall, this antenna structure steers TE 11 , TM 01 and TE 21 modes patterns which makes it an attracting solution for tracking and communication applications. The proposed antenna system has been prototyped and experimentally verified in a compact antenna test range (CATR) chamber. The measured conical scan angles for TE 11 mode is found to be around ±40 • with gain deviation less than 3 dB. The TM 01 and TE 21 modes are steered with a scan angle covering ±30 • .