antenna-theory.com

[bigSteve]

This article describes Lockheed Martin and Penn State teaming up to develop satellite antennas with "noticeable improvement".

http://blog.executivebiz.com/2011/02/lockheed-martin-penn-state-develop-breakthrough-spacecraft-technology/

Noticeable improvement is pretty ambiguous...higher efficiency, larger bandwidth, higher gain?

The article discusses the use of metamaterials. These materials often have odd epsilon (permittivity) or mu (permittivity) values that don't occur in nature. For instance, the most famous metamaterials are the "negative-refractive materials", where the relative dielectric constant and the relative permeability are simulataneously equal to -1 (giving rise to some very interested properties, one of which is negative refraction and the creation of 'perfect lenses').

It's not clear what type of materials they use from this article, I can only guess high permittivity, low-loss dielectrics that allow them to shrink the size of the antennas or decrease coupling, both desirable properties in satellites.