A substrate integrated waveguide(SIW) based antipodal linear tapered slot antenna (ALTSA) with dielectric loading at 60 GHz for inter-satellite communication applications is presented. The antenna gain is 17.29 dB at the frequency of interest with good efficiency of 95.1%. The antenna is designed using Rogers RT/Duroid 6002 material with dielectric constant 2.94 and thickness 0.254 mm. A hat-shaped dielectric loading is added to the antenna to form a dielectric guiding structure, which narrows the beamwidth. To reduce the cross-polarization levels and relative side-lobe levels, rectangular shaped corrugation is used in the antenna design. Ansys HFSS software is used for the simulation of antenna.