D. Baillargeat et al., CAD APPLYING THE FINITE-ELEMENT METHOD FOR DIELECTRIC-RESONATOR FILTERS, IEEE transactions on microwave theory and techniques, 46(1), 1998, pp. 10-17
The progress of numerical techniques now permit us to analyze rigorous
ly complex devices such as dual-mode cavity multipole filters or plana
r passive elements for coplanar monolithic microwave integrated circui
ts (MMIC's), In this paper, we describe a rigorous design of dielectri
c resonator (DR) filters applying the finite-element method (FEM), We
first present a dual mode coupling technique which replaces classical
DR's, coupling, and tuning screws, which are commonly used in dual-mod
e filters, by slotted DR's. Next, a new theoretical analysis based on
the contribution to the dual-mode filter response of the first DR hybr
id mode and of higher order modes is described, This analysis can be a
pplied to any type of microwave dual-mode filter, It allows us to defi
ne a procedure which explains the presence and controls the position o
f the two transmission zeros in the filter responses, In this paper, t
his procedure has been applied to improve filtering performances of a
dual-mode DR filter, Finally, a synthesis method is developed to rigor
ously design for the first time, a four-and an eight-pole slotted DR e
lliptic filters, The experimental results were obtained with no tuning
and the theoretical ones show good agreement.