The invention discloses an ultra-thin wave absorber based on deep sub-
wavelength slits, which is characterized in that the thickness of a
unit structure of the ultra-thin wave absorber is a deep sub-
wavelength scale, namely, one percent
wavelength magnitude and below, the ultra-thin wave absorber is divided into three
layers along the height direction, namely, a
metal patch, a
dielectric spacer layer and a
metal back plate from top to bottom, and an air slit with a deep sub-wavelength width is arranged between adjacent
metal patches; the
dielectric spacer layer is made of a low-loss material with the loss tangent value tan[
delta] being less than 0.01, or the
dielectric spacer layer is made of a lossless material; the wave absorbing wavelength is changed by changing the size of the metal patch and adjusting the thickness of the dielectric spacer layer so as to achieve
wave absorption, and the wave absorber can work in all frequency bands from terahertz, microwaves to
radio frequency. The thickness of the wave absorber is very small, the thickness of the wave-absorbing device is reduced to a few hundredths of wavelength from the traditional a few tenths of wavelength, and the wave absorber is very thin and light in weight and has certain flexibility; a mature circuit board process can be adopted for manufacturing, and the cost is reduced; and the wave absorbing effect is not sensitive to the incident angle, and the wave absorber has a conformal
advantage and can cover the curved surface.