Abstract: A high-gain omnidirectional antenna module includes a base, an RF power amplifier, an omnidirectional antenna, a first signal line, and a second signal line. The base has a first surface and a second surface. The first signal line delivers a signal fed from outside to an input port of the RF power amplifier, and the second signal line connects an output port of the RF power amplifier and a feed portion of the antenna. The signal is amplified by the RF power amplifier, and thus the gain of the omnidirectional antenna is increased significantly. Therefore, the high-gain omnidirectional antenna effectively increases the transmission distance without increasing the size of the omnidirectional antenna.