Tunable SIW Slot Antenna Constructed by High Permittivity Material

A novel substrate integrated waveguide (SIW) bowtie slot antenna with tunable operation frequency is presented. The tunable is done by covering a high permittivity BST dielectric thick film into the radiation slot similar to a bowtie. The radiation frequency is sensitive to the variation of the dielectric constant of the Barium Strontium Titanate (BST) ceramic. Specifically, the return loss up to -36dB is observed at the center frequency of 6.07GHz when the dielectric constant of BST is 330. The center frequency shifts from 5.31GHz-7.17GHz when the dielectric constant of the BST increases from 490 to 180. Within the tunable frequency range, the antenna gains are more than 5dBi. The radiation patterns and the gains are almost not affected by the variation of the dielectric constant of BST, which shows outstanding features of this very compact and easy fabricated tunable antenna. As a result, the presented antenna has great potential for the applications in tunable frequency selection metamaterials devices.