Design of a High-gain Dual-frequency Omnidirectional Antenna

Anomnidirectional high-gain antenna is realized using a composite structure. Two groups of omnidirectional high-gain antenna elements operating on different frequency bands are placed on the same plane. Each group of antenna elements is composed of four directional dipole antennas, and the directional dipole antenna array produces an omnidirectional radiation pattern in space through reasonable spatial arrangement and feed network design. The designed antenna operates in the frequency rage 760 MHz-1100 MHz and 1380 MHz-1580 MHz. The VSWR is less than 2, the pattern roundness is less than 2.5 dB, and the realized-gain is greater than 5 dBi.