Frequency selective plate and method for producing same

A frequency selective plate having a radio wave transparent property, said frequency selective plate comprising:

• a transparent substrate;
• a first mixture layer formed on said transparent substrate, said first mixture layer comprising a mixture of a metal nitride and Ag;
• a second mixture layer formed on said first mixture layer, said second mixture layer comprising a mixture of a metal nitride and Ag;
• and
• Ag particles formed on said second mixture layer, said Ag particles being two-dimensionally distributed on said second mixture layer and being separated from each other.

A method for producing a frequency selective plate, said frequency selective plate comprising:

• a transparent substrate;
• a mixture layer formed on said transparent substrate, said mixture layer comprising a mixture of a metal nitride and Ag;
• and
• Ag particles formed on said mixture layer, said Ag particles being two-dimensionally distributed on said mixture layer and being separated from each other,
• wherein said mixture layer comprises (a) a three-dimensional skeleton of said metal nitride and (b) clusters of said Ag, said clusters are separately and three-dimensionally distributed in said three-dimensional skeleton of said metal nitride, and each cluster of said Ag is an aggregate of Ag atoms and has a size smaller than that of each Ag particle, said method comprising the steps of:
• (a) forming a precursory layer on said transparent substrate, said precursory layer comprising a precursory mixture of said metal nitride and said Ag;
• and
• (b) heating said precursory layer into said mixture layer such that said Ag particles, which originate from said Ag of said precursory layer, are formed on said mixture layer.