difference between ebg and metamaterial?

Hi hosein527,

I asked my supervisor the same question when I started in graduate school, as my master's thesis was on metamaterial EBGs.

A metamaterial (loosely defined) is a composite, which is generally arranged in periodic arrays. These arrays form an "effective" medium, which can possess properties not usually found in nature - e.g., left-handed "backwards" propagation.

An EBG on the other hand, is also a composite structure which is generally arranged in periodic arrays. However, the EBG does not need to be viewed as an effective medium, and more pointedly, it is used for its band gap properties.

A metamaterial may be used as an EBG, if it possesses the appropriate band gap. Alternatively, an EBG can be a metamaterial, if it makes use of mechanisms such as backwards wave propagation, and meets the effective-medium limit.

So the two may be related, but there is no requirement that they be.

Hope this helps!