In this paper the powders of Zn1-xCoxO (x=0, 0.01, 0.02, 0.025, 0.05, 0.1) were fabricated by the conventional solid state reaction. The crystal structure was characterized by x-ray diffraction (XRD). The electromagnetic parameters were measured using vector network analyzer (VNA), the infrared emissivity in the wavelength range of 3-5μm and 8-14μm was measured by Dual-band infrared emissivity measuring instrument. The absorption bandwidth of the double-layer microwave absorber is obviously more than that of the single-layer absorber. The bandwidth of the double-layer microwave absorber for reflection loss R<-8dB is 2.64GHz over the range of 8.2-18GHz. The thickness of the absorbers is only 4 mm. The infrared emissivity is only 0.39 in the range of 3-5μm and 0.81 in the range of 8-14μm.
Dual-band negative index metamaterial: double negative at 813 nm and single negative at 772 nm