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The spectral emissivity of the surface of the selective Radiator varies with the wavelength. The selective radiator can be prepared by periodic structure, which has strange electromagnetic characteristics. HFSS software is used to construct the frequency selection surface based on periodic structure. The structural material is metal gold, the dielectric layer material is silicon dioxide, and the resonance unit parameters are in the micron scale. The modulation characteristics of the electromagnetic wave transmittance in the infrared band are calculated. Through calculation, it is found that the designed selective radiators have very low emissivity on both the mid-infrared 3-5mm atmospheric window and far-infrared 8- 14mm atmospheric window. The resonant central frequency point in the mid-infrared atmosphere window moves from 4.6mm to 4.9mm.In the mid-infrared 3.33 -6.17mm band, transmission rate is below 0.1. In the far-infrared 7.43 -12.2mm band, transmission rate is lower than 0.1.The influence of the structure on the electromagnetic transmission characteristics is recalculated by changing the thickness of the dielectric layer. It is found that the thickness of the dielectric layer has little influence on the resonance center of low transmittance, and the influence is mainly on the bandwidth and the peak value of high transmittance. A change in the dielectric layer's dielectric constant will also cause a change in the position of the resonant frequency. When the dielectric constant increases from ε= 2.9 to ε=5.9, the location of the resonant frequency changed obviously. The resonant wavelength in the far-infrared atmospheric window moves from 8.72mm to 11.36mm. As the dielectric constant increases, the resonant wavelength moves towards the long wave.
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