REALIZING FREQUENCY RECONFIGURABLE ANTENNA BY FERRITE-LOADED HALF-MODE SIW

We propose and experimentally demonstrate a frequency reconfigurable antenna using ferrite loaded half-mode substrate integrated waveguide (SIW). The antenna design is based on a SIW cavity with an embedded ferrite slab, which causes the resonant frequency of the cavity tunable under bias magnetic field. The antenna features omnidirection radiation and small size. A prototype antenna is designed and fabricated. The measurements show the tunable frequency bandwidth is over 11% covering frequencies 5.04-5.62 GHz in low bias magnetic field region, and 5% covering 4.28-4.5 GHz in high bias magnetic field region. The measurement is in good agreement with simulations. The gain of antenna is all over 1.6 dBi, and the frequency reconfiguration does not affect the radiation pattern of the antenna, providing a preferable feature for frequency reconfigurable antenna. This type of antenna may be a good candidate for practical applications such as base stations and satellites. (C) 2017 Wiley Periodicals, Inc.