Figure 2
From: A frequency reconfigurable dipole antenna with solid-state plasma in silicon

(a) Overall configuration of the proposed frequency reconfigurable dipole antenna. Black box with dotted line indicates the plasma radiator. (b) Optical photograph of the fabricated silicon wafer with a plasma radiator. (c) Optical photograph of the fabricated plasma radiator. Close-up view of the black box with dotted line. Red box with dotted line indicates the plasma channel. (d) Structure of the segment composed of serially connected p-i-n diodes. Metal lines are intentionally not drawn here. One segment makes a single plasma channel. (e) Fabrication flow of the unit p-i-n diode.