Magnetically Reconfigurable SIW Antenna with Tunable Frequencies and Polarizations

We propose a novel reconfigurable substrate-integrated waveguide (SIW) slot antenna with frequency and polarization tunability. Based on the multimode characteristic of SIW resonant cavity, the antenna works in two bands and radiates in linear or circular polarizations by tuning a crossed radiation slot. With the loading of ferrite slabs, the polarizations and operation frequencies of the antenna can be tuned by varying the bias magnetic field (BMF). The proposed design is verified by both simulations and experiments. The measurement results show that the tunable frequency range is more than 8.1% in the lower frequency band (from 8.98 to 9.74 GHz) and 5.5% in the higher frequency band (from 9.98 to 10.54 GHz). The antenna gain is more than 5.1 dBi within the frequency tuning range. The radiation pattern of the antenna is almost not affected by the changes in the BMF.