This paper studies the performance of a submillimeter wave antenna operating between frequencies 0.1 THz and 10 THz with a 4-cyano-4-pentylbiphenyl [5CB] substrate. Since the size and shape of the antenna impact its gain/directivity, resonant frequency, bandwidth, and efficiency, the two antenna types considered in this paper are: (a) Rectangular Patch Antenna (RPA), and (b) Cylindrical Dielectric Resonator Antenna (CDRA). Here a submillimeter wave antenna is compared with a millimeter wave (a few GHz to 100 GHz) antenna. These popular mm-wave antennas are chosen for the submillimeter wave antenna in order to understand changes in their performance as the result of changes in their geometrical shape. FEldberechnung bei Korpern mit beliebiger Oberflache (FEKO) software is used for the design and calculation of the Three-Dimensional (3D) ElectroMagnetic (EM) patterns. This paper also concentrates on the design and analysis of a massive submillimeter wave Multiple-Input Multiple-Output (MIMO) (8 by 8) RPA and CDRA.