Abstract: The design method of the airborne conical log-spiral antennas fed with two types of excitation is presented. The conical log-spiral antennas fed with two types of excitation are simulated and optimized by commercial EDA software FEKO. The simulated resuhs show that the characters of this antenna are enough to content application. On this condition, the prototype of the antenna is constructed and measured. The proposed antenna designed working from 2.5GHz to 8GHz has the characters that 3dB beam width is about 100°, axial ratio is less than 3dB, and VSWR is less than 2. The measured results agree well with simulated ones. The measured results show that the conical log-spiral antennas are of wide band, wide beamwidth and circular polarization. In addition, the measured results show that this design method is valid and it can be applied.