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 omni‐direction 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. © 2017 Wiley Periodicals, Inc. Microwave Opt Technol Lett 59:1365–1371, 2017

We theoretically and experimentally studied a transmitting-absorbing material that had transmission window within the absorption band. The material had a sandwich structure comprised of a resistive metasurface, a dielectric substrate and a metallic slot frequency-selective surface (FSS). The material showed lower reflectivity in a wide frequency range; the -10 dB absorbing bandwidth could be over 76% (64% in experiments). Meanwhile in the middle of the range the transmittance up to -1.7 dB was observed at about 10 GHz where slot FSS had good transparency. We showed the lower reflectivity of our material was mainly due to the absorption of incident radiation energy except for the transparent window where the radiation energy passed through the materials. The transmitting window could be adjusted by changing the geometry parameters of slot FSS. Our material had the advantages of thin thickness, small size of unit cell, convenient fabrication and easy to extend to other frequency bands. This kind of transmitting-absorbing material provided a new way for the applications, such as light harvesting, sensing and radome materials.

No abstract

No abstract

No abstract