This paper proposes sector-Beam transmitting antennas for 79GHz automotive short range radar (SRR) application. The antennas with three channels have different beam directions, respectively, to cover a wide detection area. A microstrip patch array technique is used to implement the sector-beam antennas and antenna prototypes are fabricated and measured. The measurement results of the prototypes verify the possibility for this application. A 79 GHz SRR sensor is manufactured using the proposed antennas and will be tested in the near future.