In this work, we present a new design of a low loss and high birefringence THz Photonic Crystal Fiber (PCF) made of TOPAS material, featuring a porous core with elliptical holes. The full-vector finite element method was employed to analyze the optical properties such as birefringence, confinement losses, and effective material losses; as well as to study how these parameters are dependent on the geometry of the structure. The simulation results showed confinement losses ≈ 0.06 dB/m when a configuration with high grade of porosity in the core was implemented. At the same time, birefringence values close to 3×10^-2 there were obtained. The proposed design can be fabricated easily using standard stack and draw technique and be used in several applications in the THz region to propagate the radiation.