In this paper, a new waveguide slotted antenna array, in which T-shaped cross section waveguide is used as the radiating waveguide, is proposed and simulated. The T shaped radiating waveguide can reduce the waveguide profile height. The radiating slots are etched and inclined alternately on the top. The metal fences are introduced between slots to repress the sidelobe level of E-plane. A bend structure is invented to feed the T-shaped radiating waveguide. A 2 × 6 antenna array working at Ka-band is designed and the obtained simulated results demonstrate this novel structure.