Reseach On Reconfiguration Of Microstrip Antenna Loaded With BST Ferroelectric Film

With rapid development of integrated information system featured large capabilities and wide bandwidths, the carriers need more information subsystems, which makes the number of receiving and transmitting antennas increased. Numerous problems such as weight increased and electromagnetic interference between antennas and so on are brought about. The above questions can be solved by reconfigurable antenna.The research of reconfigurable antenna based on microstrip antenna is widely studied, because of light weight, low cost, low profile, easy to shape of microstrip antenna. Traditionally, the frequency, pattern and polarization reconfigurable antennas are realized by using PIN diodes or MEMS switches.A novel reconfigurable method is investigated in this paper. The frequency and pattern reconfiguration antennas are constructed by loading BST ferroelectric film on microstrip antenna. Easy to adjust parameters, continuous to tune frequency, uniform to scatter electric field are characterized by this novel method. The major researches are listed as follows:Firstly, the mechanism of frequency reconfiguration of microstrip antenna loaded BST ferroelectric film is studied. The influences of BST ferroelectric film position and parameters on resonant frequency, input impedance and pattern are discussed. In addition, the frequency reconfiguration is achieved by loading BST ferroelectric film on ordinary microstrip patch antenna and microstrip dipole antenna seperately.Secondly, the mechanism of pattern reconfiguration of microstrip Yagi antenna loaded BST ferroelectric film is studied. The radiation characteristic of two-unit microstrip Yagi antenna is investigated. The conversion between direction and reflection of the passive patch is realized by loading BST ferroelectric film at the edge of it. What’s more, BST ferroelectric film is loaded at the edge of two passive patchs of three-unit microstrip Yagi antenna. By changing the relative value of dielectric constant of BST ferroelectric film, the pattern reconfiguration is realized. By cutting slots on the active patch, the pattern reconfiguration antenna is improved.