TITLE:
Elevated Ferrite Film Circulator with Different Permittivities for Layers: An Analytical Expression for the Input Conductance Employing Perturbation Method
AUTHORS:
Arash Rashidi, Ali Banai
KEYWORDS:
Elevated Ferrite Circulator, Perturbation Integral, Splitting Factor, Dipolar Resonant Frequencies
JOURNAL NAME:
Journal of Electromagnetic Analysis and Applications,
Vol.2 No.9,
October
12,
2010
ABSTRACT: The main idea of this paper is to find an analytical formula for the input conductance of an elevated ferrite film circu-lator to match it systematically to the desired matching network. For solving the ferrite loaded dielectric resonator included in stripline elevated ferrite film circulator, the off diagonal components of the permeability tensor are taken as the perturbation. The electromagnetic fields computations are done for unperturbed structure. The dipolar resonant frequencies corresponding to harmonics of the resonant modes are then calculated using the perturbation integrals. The quality factor of the circulator is derived in terms of these dipolar resonant frequencies. Energy integrals are calculated to find the energy stored in the ferrite and dielectic layers. An analytical expression for the input conductance of the elevated ferrite film circulators is derived by using the quality factor and energy integrals. In this expression the ferrite and dielectric layers can have different permittivities. Some discussions about the effect of ferrite film thickness and permittivity mismatch on the bandwidth of the circulator are investigated by HFSS commercial software.