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In order to investigate the effect of magnetic metal on the absorption performance of metamaterial absorber (MMA), a dual-peak MMA based on magnetic metal nickel is designed and demonstrated in the P-band (300–1000 MHz). Two-layer square-ring-metal resonator arrays and two-layer dielectric substrates are arranged alternately with each other to constitute the proposed dual-peak MMA backed with a reflective metal plate. The influences of copper or nickel metallic layers on the absorption coefficients are comparatively analyzed. For the nickel MMA, the dual-peak absorption coefficients of 99.82% and 99.09% are achieved at 394 MHz and 605 MHz, respectively. Moreover, the thickness of dual-peak MMA could be reduced to 9 mm by employing magnetic metal nickel. The physical mechanism of dual-peak absorption is illustrated by surface current distributions, magnetic field distributions and power loss density distributions. The relationship between the changes of geometric dimensions and the shift of peak absorption frequencies is ultimately discussed. These results could provide instructive guidance for realizing a thin dual-peak MMA in the P-band. [ABSTRACT FROM AUTHOR]

This paper is aimed at acquiring functional ceramics with broadband magnetoelectric (ME) response for sensing wide-range of dc bias magnetic field. Three-phase particulate ceramics CoFe2O4/Ni0.8Zn0.2Fe2O4/Bi0.5Na0.4K0.1TiO3 (CFO/NZFO/BNKT) were fabricated, and the effect of magnetostrictive phase on the piezoelectric, magnetic, and ME properties were investigated systematically. Separated phases and homogeneous microstructure of the magnetostrictive and piezoelectric phases were confirmed. The variation in magnetostrictive coefficient with dc magnetic field was found to be markedly dependent on the relative content of magnetostrictive microparticles. By merging the nonlinear piezomagnetic response of the two ferrite components together, the ME composites present dual-peak bands. A wide-range ME coefficient was achieved over a magnetic range of 1800 Oe with large ME value of 20 mV/cm Oe. This field-conversion broadband ME behavior indicates that three-phase particulate ME ceramics are quite preferable for practical applications in magnetic field sensor. [ABSTRACT FROM AUTHOR]