Mastering of the terahertz frequency band is attractive for numerous practical applications. Fabrication tolerances of widely used computer numerical control machining result in vital increase of input optics losses of active waveguide components at frequencies beyond 1 THz. This issue can be resolved if conventional hollow metallic waveguide technology is replaced by that making use of wave propagation in low-loss dielectric media. In this paper we report on the development of parametric model of a terahertz dielectric rod antenna array. Both analytic and numeric analysis for variety of the antenna array geometries are provided. The developed parametric model can be used to rigidly construct the dielectric rod antenna array with desired beam parameters at any frequency in the terahertz band if the antenna form factor is fixed and Si platform is used. We believe that our findings are of practical importance to terahertz photonics engineers.