Passive electromagnetic decoupling in an active metasurface of dipoles

Passive electromagnetic decoupling in a very dense array of resonant active dipoles is a challenging task. Here we consider the decoupling of three very closely located resonant dipoles by two similar passive dipoles. In the non-resonant case it is not reducible to the decoupling of two active dipoles by a passive one. However, in the present case when the active dipoles have the resonant length their approximate decoupling is really achievable in the same way for both dimer and trimer of active dipoles. We prove this fact analytically, verify numerically and validate experimentally. Decoupling allows one to use different elements of the array in both transmitting and receiving regimes simultaneously that can be treated in terms of an active metasurface.