Before revision: Field displacement This type is superficially very similar to a resonance absorption isolator, but the magnetic biassing differs, and the energy from the backward travelling signal is absorbed in a resistive film or card on one face of the ferrite block rather than within the ferrite itself.
After revision: Field displacement This type is superficially very similar to a resonance absorption isolator, but the magnetic biasing differs, and the energy from the backward travelling signal is absorbed in a resistive film or card on one face of the ferrite block rather than within the ferrite itself.