A four-stage switched beam antenna array at millimeter-wave (mm-wave) frequencies is designed, fabricated, and experimental results are demonstrated. A novel rectangular loop dipole antenna (RLDA) applying the quasi Yagi-Uda concept is designed to achieve high gain and wide bandwidth with end-fire radiation. This RLDA with director has a return loss better than 10 dB over a frequency range of 32 GHz to 37 GHz and a peak gain of 8.5 dB. The proposed high gain end-fire RLDA antenna in combination with a 4x4 Butler Matrix(BM) creates the switched beam configuration and generates four beams in the directions of 15˚±2˚, -45˚±4˚, 38˚±2˚, and -15˚±1˚ at 33.5 GHz, 34.5 GHz, and 35.5 GHz with successive input port excitation. The switched beam configuration has overall dimensions at 34.5 GHz is 26 mm x 25.8 mm (3.03λ x 3.0λ).