Broadband terahertz (THz) technology has widespread applications in the fields of national defense, scientific research and so on, and photoconductive antenna is an essential approach to generate THz wave. The impact of growing and annealing temperatures on material carrier lifetime and resistivity was analyzed. Four small-aperture photoconductive antennas of BowTie and Dipole structures were fabricated on low-temperature-grown GaAs (LTG-GaAs) grown at 230 ℃ and 250 ℃ respectively, and annealed at 475 ℃. As a result, the 250 ℃ grown antennas have higher THz wave output power and broader spectrum up to 3.6 THz, in contrast to the 230 ℃ grown one. In addition, the output power generated by BowTie antenna is stronger than Dipole antenna. Moreover, it is verified that both of the small-aperture photoconductive antennas can generate THz wave under 10 V bias voltage.