| 摘要 |
PROBLEM TO BE SOLVED: To absorb radio wave over a wide band from sub-millimetric wave band to millimetric wave band by specifying the thickness of a dielectric layer and return loss. SOLUTION: The radio wave absorber has a conductive layer and a dielectric layer wherein the thickness of the dielectric layer is 5 mm or less and the permittivityε' and dielectric lossε" of the dielectric layer are designed such that the return lossΓwill be 6 dB or above at frequencies 18 GHz, 50 GHz, 75 GHz and 100 GHz. Although a thinner absorber having a larger return lossΓis excellent, but when combinations of the permittivityε' and dielectric lossε' are calculated and analyzed over a wider range of frequency for practically required specifications of the return lossΓof 6 dB or above, and the thickness of 5 mm or less, required specifications are satisfied in the range of 18-100 GHz regardless of the frequency. Such a radio wave absorber is so-called wind band type and has radio wave absorption performance of 6 dB or above in the range of 18-100 GHz and degradation of characteristics due to fluctuation of thickness is negligible.
|
