Patent ID: 6563403
Filing Date: 2003-05-13
Classification: H01P

Abstract:
A dual mode band-pass filter comprising:a dielectric body having first and second main surfaces; a metal film partially disposed on the first main surface of the dielectric body or at a certain level in the dielectric body, the metal film having one of an opening, a protrusion, and a cut-out arranged to combine two resonant modes; a ground electrode disposed on the second main surface or in the interior of the dielectric body so as to be opposed to the metal film via a portion of the dielectric body therebetween; and a pair of input-output coupling circuits being coupled with different portions of the metal film; wherein the dielectric body includes a dielectric ceramic containing a ceramic and a glass as main constituents, and is capable of being fired simultaneously with any one of Cu, Ag, and Au, and having a Q value of more than approximately 300 at about 10 GHz; wherein the dielectric body is made of a sintered material including a MgOâ€”MgAl2O4-based ceramic powder and a glass powder containing about 13% to about 50% by weight SiO2, about 3% to about 60% by weight B2O3, and about 0% to about 20% by weight Al2O3.