Patent ID: 6597264
Filing Date: 2003-07-22
Classification: H01P

Abstract:
A microwave filter comprising a plurality of composite resonators each one comprising a cavity (A; B; 2) and a dielectric resonator (R;3) housed inside said cavity, and at least one coupling (V; 4, 8) between two adjacent composite resonators, said composite resonators being of the monomode type and having a resonant frequency that corresponds to a mode of electromagnetic resonance of a hybrid electromagnetic family comprising electric field and magnetic field patterns, wherein:the dielectric resonators (R; 3) of at least two adjacent cavities are located in a same reference plane or in parallel reference planes, said reference plane being that which sections the dielectric resonator into two symmetrical halves and on which the electric field patterns (a1, a2) of degenerated orthogonal modes are essentially equal but turned through 90Â° with respect to each other; a respective originally degenerated resonant mode of each one of said resonators is perturbed by altering its resonant frequency to thereby separate the resonant frequencies of the orthogonal modes in each of said composite resonators; and the filter has a main path (7) for a microwave signal that traverses the composite resonators in a first sequence and at least one alternative path (11) for the signal through said cross coupling and through at least some of said composite resonators in a second sequence different from said first sequence.