# US 12,119,801 B2 · Multilayer LC filter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,119,801 B2 - Document ID: US12119801B2 - Status: Granted - Kind: B2 - Application number: 17/696,390 - Filed: 2022-03-16 - Published: 2022-06-30 - Granted: 2024-10-15 - Earliest claimed: 2019-10-24 - Assignees: Murata Manufacturing Co., Ltd. - Applicants: Murata Manufacturing Co., Ltd. - Inventors: Keisuke Ogawa - Web page: https://patentgrep.com/patent/US12119801B2 ## CPC - H03H 7/0115: {comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence)} - H03H 7/0161: {Bandpass filters (H03H7/12 takes precedence)} - H01F 17/00: Fixed inductances of the signal type - H01F 27/00: Details of transformers or inductances, in general - H01G 4/30: Stacked capacitors (H01G4/33 takes precedence) - H01G 4/40: Structural combinations of fixed capacitors with other electric elements, the structure mainly consisting of a capacitor, e.g. RC combinations - H03H 7/1708: {Comprising bridging elements, i.e. elements in a series path without own reference to ground and spanning branching nodes of another series path (H03H7/07 takes precedence)} - H03H 7/1775: {Parallel LC in shunt or branch path (H03H7/1791 takes precedence)} - H01G 4/012: Form of non-self-supporting electrodes - H01G 4/232: electrically connecting two or more layers of a stacked or rolled capacitor - H03H 2001/0085: {Multilayer, e.g. LTCC, HTCC, green sheets} - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES - H01G: CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE (selection of specified materials as dielectric H01B3/00; capacitors having potential barriers H10D1/62, H10K10/10) ## Abstract A multilayer LC filter includes a multilayer body in which insulator layers, a ground electrode, capacitor electrodes, a planar electrode, and via electrodes includes open-side via electrodes connecting the capacitor electrodes and the planar electrode and short-circuit side via electrodes connecting the planar electrode and the ground electrode, an inductor is provided by a conductive path extending from the capacitor electrodes to the ground electrode through the open-side via electrodes, the planar electrode, and the short-circuit side via electrodes, a capacitor is provided by capacitance generated between the ground electrode and the capacitor electrodes, the inductor and the capacitor are connected in parallel to define LC resonators, and it is assumed that the short-circuit side via electrodes of all of the LC resonators in the multilayer body are made common. ## Claims ### Claim 1 A multilayer LC filter comprising: a multilayer body including insulator layers laminated in a lamination direction; at least one ground electrode between the insulator layers; a plurality of capacitor electrodes between the insulator layers; at least one planar electrode between the insulator layers; and a plurality of via electrodes extending the insulator layers; wherein the multilayer body has a rectangular or substantially rectangular parallelepiped shape and has a height direction that is the lamination direction, a length direction orthogonal to the height direction, and a width direction orthogonal to each of the height direction and the length direction; the via electrodes include open-side via electrodes connecting the plurality of capacitor electrodes and the at least one planar electrode and a short-circuit side via electrode connecting the at least one planar electrode and a ground electrode; an inductor is provided by a conductive path extending from the plurality of capacitor electrodes to the ground electrode through the open-side via electrodes, the at least one planar electrode, and the short-circuit side via electrode; a capacitor is provided by capacitance generated between the ground electrode and the plurality of capacitor electrodes; the inductor and the capacitor are connected in parallel to define an LC resonator; and a plurality of the LC resonators are in the multilayer body; each of the plurality of the LC resonators includes a respective one of the open-side via electrodes; the short-circuit side via electrode is a common electrode of all of the LC resonators in the multilayer body; the plurality of LC resonators include four LC resonators in the multilayer body; and when viewed in the lamination direction, the respective open-side via electrodes of the four LC resonators are separately positioned at four corners in the multilayer body. ### Claim 2 (depends on 1) The multilayer LC filter according to claim 1, wherein in the length direction of the multilayer body, the short-circuit side via electrode that is the common electrode for all of the LC resonators is between the open-side via electrode of at least one of the LC resonators and the open-side via electrode of at least one of the other LC resonators. ### Claim 3 (depends on 1) The multilayer LC filter according to claim 1, wherein in the width direction of the multilayer body, the short-circuit side via electrode that is the common electrode for all of the LC resonators is between the open-side via electrode of at least one of the LC resonators and the open-side via electrode of at least one of the other LC resonators. ### Claim 4 (depends on 1) The multilayer LC filter according to claim 1, wherein the short-circuit side via electrode that is the common electrode for all of the LC resonators includes a plurality of the via electrodes. ### Claim 5 (depends on 4) The multilayer LC filter according to claim 4, wherein the via electrodes of the short-circuit side via electrode that is the common electrode are equally spaced in the width direction. ### Claim 6 (depends on 4) The multilayer LC filter according to claim 4, wherein the via electrodes of the short-circuit side via electrode that is the common electrode are eccentrically located in the width direction. ### Claim 7 (depends on 1) The multilayer LC filter according to claim 1, wherein the at least one planar electrode is a planar electrode of all of the LC resonators that is a common electrode. ### Claim 8 (depends on 7) The multilayer LC filter according to claim 7, wherein when viewed in the lamination direction of the insulator layers, the planar electrode that is the common electrode for all of the LC resonators has a rectangular or substantially rectangular shape. ### Claim 9 (depends on 8) The multilayer LC filter according to claim 8, wherein a slit is located in the planar electrode that has the rectangular or substantially rectangular shape and is the common electrode. ### Claim 10 (depends on 1) The multilayer LC filter according to claim 1, wherein a first input/output terminal and a second input/output terminal are provided on an outer surface of the multilayer body; n number of the LC resonators are provided in the multilayer body, where n is an integer; the n number of the LC resonators are coupled in order; the first input/output terminal and a second stage of the LC resonator are connected via a capacitor; and an (n−1)-th stage of the LC resonator and the second input/output terminal are connected via a capacitor. ### Claim 11 (depends on 10) The multilayer LC filter according to claim 10, wherein the four LC resonators are coupled in order; the first input/output terminal and a second stage of the four LC resonators are connected via a capacitor; and a third stage of the four LC resonators and the second input/output terminal are connected via a capacitor. ### Claim 12 (depends on 1) The multilayer LC filter according to claim 1, wherein the at least one planar electrode includes a plurality of planar electrodes; each of the planar electrodes is between different layers of the insulator layers; at least one of the open-side via electrodes is connected to one of the planar electrodes; at least one of the other open-side via electrodes is connected to one of the other planar electrodes between different layers; and the short-circuit side via electrode that is the common electrode is connected to all of the planar electrodes between different layers. ### Claim 13 (depends on 10) The multilayer LC filter according to claim 10, wherein a first and a second of the n number of the LC resonators are electromagnetic field coupled to each other, the second and a third of the n number of the LC resonators are electromagnetic field coupled to each other, and the third and a fourth of the n number of the LC resonators are electromagnetic field coupled to each other. ### Claim 14 (depends on 1) The multilayer LC filter according to claim 1, wherein the multilayer LC filter is a four-stage band pass LC filter. ### Claim 15 (depends on 1) The multilayer LC filter according to claim 1, wherein two slits are located in the at least one planar electrode. ### Claim 16 (depends on 15) The multilayer LC filter according to claim 15, wherein one of the two slits is located between first and second LC resonators and the other of the two slits is located between third and fourth LC resonators. ### Claim 17 (depends on 1) The multilayer LC filter according to claim 1, wherein three slits are located in the at least one planar electrode, a first of the three slits being located between first and second LC resonators, a second of the three slits being located between the second LC resonator and a third LC resonators, and a third of the three slits being located between the third LC resonator and a fourth LC resonators. ### Claim 18 (depends on 1) The multilayer LC filter according to claim 1, wherein the multilayer LC filter is one of a band pass filter, a low pass filter, or a high pass filter.