In materials science, radiation-absorbent material (RAM) is a material
which has been specially designed and shaped to absorb incident RF radiation
(also known as non-ionising radiation), as effectively as possible, from as
many incident directions as possible. The more effective the RAM, the lower
the resulting level of reflected RF radiation. Many measurements in
electromagnetic compatibility (EMC) and antenna radiation patterns require
that spurious signals arising from the test setup, including reflections, are
negligible to avoid the risk of causing measurement errors and ambiguities.
…