This letter proposes a tapered stacked microstrip antenna for application in small unmanned aerial vehicles (UAVs), which has advantages in mountainous terrains. With its tapered structure and increased bandwidth designed to operate at the resonance frequency of 2.4 GHz, the proposed antenna improves directivity, accuracy, and precision of small UAVs. The test flight results show the proposed tapered antenna has a three times higher impedance capability of 350 MHz based on VSWR<2. The transmission pattern is also more reliable than that of previous antenna designs.