artificial dielectric

They are generally small particles or bits of metals that are suspended in a low dielectric material or even in air if there are rod connectors between them.

They were invented in the 1939-1945 war or at least were perfected then. These materials are then shaped into lenses.

Many decades ago there was a patent issued on a multilayer PC board with different metal square patterns/sizes on each layer. It was only a mm or two thick but acted as a relatively good lens for placement over a horn antenna to improve the radiation pattern. It also sealed the horn so that dry nitrogen could be used to pressurize it so that atmospheric humidity would not get inside.

how i can design an patch antenna using artificial dielectric?/ can u send me some paper on artificial dielectric?// plz ..........

plz help..