| In mobile communication, the indoor business possesses a high proportion, so the research onthe indoor antenna is crucial for the development of the mobile communication. An omnidirectionaldual polarized antenna and a directional dual polarized antenna are proposed in this thesis. Thebandwidths of the antennas cover1.7—2.7GHz.First of all, the single dipole antenna with a parasitic unit is presented. This antenna is based onthe theory of the dipole antennas, after adding the parasitic unit to increase the band, the antennacan work from1.57to2.97GHz and the radiation pattern of the antenna meets the requirement.Secondly, the omnidirectional dual polarized antenna is designed. It is made up by horizontallypolarized part and vertically polarized part. Based on the single dipole antenna with a parasitic unit,we work out the horizontally polarized antenna works at1.7~2.7GHz with four single additionalparasitic unit dipole antennas, which focus on the design of the feeding network and balun structure.The vertically polarized antenna based on the monopole theory is realized, and the antenna’s workband is1.5~2.9GHz.What’s more the omnidirectional dual polarized antenna has a good isolationthat more than32.7dB.At last, the directional dual polarized antenna is realized with two dipole antennas mentionedin the first part. The two units are placed at±45odegree angle on a ground plate. The antenna getsdirectional radiation performance within1.7~2.7GHz, and its max gain can reach9.45dBi thatmuch larger than the gain of single dipole antenna with a parasitic unit. |
