In this paper, a novel sierpinski carpet fractal based Photonic Band Gap (PBG) structure has been proposed. Whereas the square lattice shaped PBG consisting of drilled holes of radius r1=0.8 cm placed at a periodicity of p=3 cm, offers a band gap from 1.6 GHz to 1.95 GHz for a dielectric material of εr=9.8, the addition of secondary holes of radius r2=0.15 cm placed at a distance of δ=1 cm, from the central hole offers a wider band gap from 1.64 GHz to 2.04 GHz. This same structure is then investigated at THz frequency range by keeping the ratio of periodicity of holes to the operating wavelength, constant. Thus, the band gap now shifts to 16.4 THz to 20.4 THz. The proposed PBG can offer effective solutions to PBG based optical fibers and nano antennas for THz and optical communication applications.