Multi-mode frequency reconfigurable antenna for multi-band application
In order to cope with the problems of single frequency reconfigurable mode,large size and narrow operating band,a multi-mode frequency reconfigurable microstrip slit antenna for C,S,X and Ku bands is designed and implemented based on the traditional microstrip slit antenna,by modifying its structure.The antenna is a forked structure with PIN diodes embedded between three forked branches and the microstrip lines,respectively.By controlling the on-state of the diodes which makes the antenna have four different modes,corresponding to single-band,dual-band,tri-band and quad-band,respectively.The size of this antenna is 20mm×22mm,which is reduced by more than 20% than conventional slit antennas,resulting in miniaturization.The antenna has a maximum gain of 5 dBi at the operating frequency point and has good radiation characteristics.