  In this paper, we present a Bound states in the continuum (BIC) metamaterial
in heterogeneous structures based on the universal coupled mode theory. We find
the more general physical parameters to represent BIC, which are the resonant
frequencies and corresponding phases of metamaterial structures. Therefore, BIC
metamaterial comes from the equal value of the resonant frequencies and phases
of metamaterial structures which are not only for homogeneous structures.
Meanwhile if slightly vary one of metamaterial structure's resonant frequency
and phase by varying geometry, we can obtain the quasi-BIC instead of broken
symmetry of homogeneous structures. In this paper, we provide the BIC and
quasi-BIC with one example of two heterogeneous structures which are cut wire
(CW) and Split-Ring Resonator (SRR), to widely extends the metamaterial BIC
beyond common sense. Furthermore, we demonstrate the simulation results and
experimental results to proof our idea.
