Analysis and design of novel directional ultra wide-band antennas

Ultra wide-band is one of the hottest issues in the current researches on antennas. The circular monopole antenna is a kind of ultra wide-band antennas with simple structure. Firstly a novel antenna was researched. Four circular disc monopoles were placed across each other. They were considered as the feedings, and the reflection plane was planar. It could achieve dual polarization characteristics. On this basis, further study was applied to two other novel antennas. The first was changing the planar reflector to parabolic one, and the purpose was to realize wide beam, high gain and directed radiation characteristic. The other was changing the circular disc shape, and the purpose was to realize wider lower frequency bandwidth. The novel antennas were theoretic analyzed, and the S- parameter and radiation patterns of the antennas were discussed by electromagnetism simulation software. The analytic results verify that the characteristic of the traditional monopole antenna is effective improved by the novel antennas. Dual-polarization, high gain, wide beam and directed radiation characteristics of the antenna are realized. The novel antennas are suitable for the satellite and mobile communication systems with good prospects.