A basic study of millimeter-wave absorber for two frequency bands using transparent resistive films

A new millimeter-wave transparent wave absorber for two frequency bands of 60 and 76GHz is proposed, fabricated and evaluated. First, we discuss the structure of the transparent wave absorber consisting of a spacer and three transparent resistive films. In this structure, two sheets are absorption films and the other one is a reflection film. The proposed absorber is designed and fabricated, and its absorption characteristics are measured. As a result, we have confirmed that the peak absorption of 20 dB or more is obtained at each target frequency of 60 and 76GHz.