Patent ID: 6583687
Filing Date: 2003-06-24
Classification: H03H

Abstract:
A lamination type LC filter comprising:a laminated body comprising a plurality of dielectric sheets; a first parallel LC resonance circuit located at an input side and including an inductor and a capacitor connected in parallel, the inductor of said first parallel LC resonance circuit being defined by a first inductor electrode, and the capacitor of said first parallel LC resonance circuit being defined by a first capacitor electrode and a first internal ground electrode; a second parallel LC resonance circuit located at an output side and including an inductor and a capacitor connected in parallel, the inductor of said second parallel LC resonance circuit being defined by a second inductor electrode and the capacitor of said second parallel LC resonance circuit being defined by a second capacitor electrode and a second internal ground electrode; wherein the first parallel LC resonance circuit and the second parallel LC resonance circuit are electromagnetically coupled; each of the first and second inductor electrodes, the first and second capacitor electrodes and the first and second internal ground electrodes are provided inside the laminated body; a first end portion of the first inductor electrode is connected to the first capacitor electrode and a second end portion of the first inductor electrode is connected to the first internal ground electrode; a first end portion of the second inductor electrode is connected to the second capacitor electrode and a second end portion of the second inductor electrode is connected to the second internal ground electrode; the first capacitor electrode and the first internal ground electrode are strip-shaped, and the first capacitor electrode and the first internal ground electrode overlap each other in a perspective view in which the lamination type LC filter is seen from the top; the second capacitor electrode and the second internal ground electrode are strip-shaped, and the second capacitor electrode and the second internal ground electrode overlap each other in a perspective view in which the lamination type LC filter is seen from the top; a portion of the first inductor electrode does not overlap with the first capacitor electrode and does not overlap with the first internal ground electrode in the perspective view in which the lamination type LC filter is seen from the top; and a portion of the second inductor electrode does not overlap with the second capacitor electrode and does not overlap with the second internal ground electrode in the perspective view in which the lamination type LC filter is seen from the top.