Elevated Substrate Ferrite Film Circulator

Elevated Ferrite Film Circulator with Different Permittivities for Layers: An Analytical Expression for the Input Conductance Employing Perturbation Method

“…Finally, they designed a matching network by using Anderson's approximate formulation [15] and without electromagnetic computations for energy calculation to find input conductance of the circulator. Later Jones et al [13] reported the design of an elevated substrate ferrite film circulator having 20 dB isolation over 12-12.6 GHz without any details about the matching of their circulator. How et al [12] calculated S-parameters and losses in ferrite-film junction circulators using a new effective-field theory assuming TEM-like propagation.…”

“…In conventional circulators a ferrite cylinder fills completely the space between the central metal disk and the ground plane in stripline or microstrip structure so they are not good remedies for integration of circulators. In elevated substrate circulators a circular ferrite thin film is deposited on dielectric substrate with a fabrication technology such as chemical vapor deposition [13] and then the central metal disk is placed on the ferrite thin film. Then between the ground and central metal disk we have two cylindrical layers: ferrite thin film and dielectric substrate layer.…”