The Study of Active Periodical Structure´s Absorbing the incident wave

Structural absorb is present in this paper. Using the periodical surface´s character of band gap and impedance transition of electromagnetic crystal structure such as PBG and HIS, put the varactor diode onto the approximate HIS to join cells on top layer to realize the electronic control for periodical structure, will establish the active periodical structure. The simulation test prove that this method and technology could absorb vertical incident wave 4-14 dB on working frequency band by using single or double layer active periodical structure, and the working frequency band could be changed and controlled by electronic method also