Research On Pattern Reconfigurable Antenna With Multi-Beam Choices

With the rapid development of wireless communication technology, greater demand has been made for the antenna performance. As a novel antenna, reconfigurable antenna, which has a lot of advantages, such as small size, versatile functions, easy to implement diversity application, has attracted a lot of attention.Radiation pattern is an important character of the antenna. Taking advantage of the reconfigurable mechanism of antenna to achieve the pattern reconfigurability is an important research aspect of the reconfigurable antenna. Using pattern reconfigurable antenna can improve system gain, enhance communication security, avoid noise interference and save energy. Therefore, pattern reconfigurable antenna has become a hot research aspect in the antenna field in recent years.After a brief introduction of the development of reconfigurable antenna and basic theory of antenna, this thesis presents two kinds of pattern reconfigurable antenna with multi-beam choices, which are pattern reconfigurable antennas with five and six beam choices, respectively. The pattern reconfigurable antenna with five beam choices operates in 5.5GHz WiMAX (Worldwide Interoperability for Microwave Access) frequency band, which can get five directional reconfigurable patterns in the elevation plane of 45 degree by controlling the states of switches. Moreover, the antenna can also achieve the frequency reconfigurability by changing the depth of the U-shaped slot. The pattern reconfigurable antenna with six beam choices works in 5.2GHz WLAN (Wireless Local Area Networks) frequency band. The designed antenna with practical RF diode switches and bias circuit can achieve pattern reconfigurability with half power beam width of about 60 degree by using the single chip microcomputer to control the states of switches. Considering the pattern gain and beam width, the antenna can cover the whole azimuth plane.The structure parameters, which affect the performance of the designed antennas, are analysed and optimized by using the electromagnetic simulation software Ansoft HFSS 10.0. The fabricated antennas are measured and the measured results agree well with the simulated results.