Research Of A Dual-Band Dual-Polarized Antenna

In current communication system, the application of dual-band dual- polarized antenna satisfies the needs of communication system's upgrade, solves the problem of multipath fading, reduces the number and lowers the cost of the antennas. As the vigorous development of the mobile communication technology, the research of the dual-band dual-polarized antenna is very urgent. It is also of theoretical significance and practical value. In this thesis, one kind of the dual-band dual-polarized antenna is mainly researched.Firstly, the theory of microstrip antenna is simply analyzed. Based on the research of it, the best feeding way which is aperture coupled feeding is found. At the same time, the round patch is chosen. The use of aperture coupled feeding widens the working band and increases the isolation. Simultaneously, the application of round patch can upgrade the gain and radiation efficiency of the antenna.Secondly, because the band of the traditional microstrip antenna is very narrow. And the isolation can't meet the requirement when the coaxial-line feeding is used to realize the dual polarization. The following work lays heavy stress on analysis of the way of widening the bandwidth and developing the isolation of the antenna. The way of widening the band is realized by employing the inverted parasitic patch and the thick and low dielectric constant substance. With this treatment, the relative band of the antenna can be widened up to 20%. And by adopting the way of two H-slots arranged in a"T"configuration, the isolation is improved. And the effectiveness of these methods is proved by emulation.Thirdly, based on the analysis of the microstrip antenna above, the dual-band dual-polarized antenna is designed and simulated. The simulation results meet the results of the requirement of the antenna design. On the base of simulation, the high frequency unit of this antenna is made and tested. The test results accord with the simulation results well. Grounded on the simulation and measurement, it proves that this antenna can be the dual-band dual-polarized antenna unit.