# US 2020/0403597 A1 · Multiplexer, filter, and communication module > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0403597 A1 - Document ID: US20200403597A1 - Status: Published application - Kind: A1 - Application number: 16/903,207 - Filed: 2020-06-16 - Published: 2020-12-24 - Earliest claimed: 2019-06-24 - Assignees: Taiyo Yuden Co., Ltd. - Applicants: Taiyo Yuden Co., Ltd. - Inventors: Hirotaka TAKEUCHI - Web page: https://patentgrep.com/patent/US20200403597A1 ## CPC - H03H 7/463: {Duplexers} - H03H 7/465: {having variable circuit topology, e.g. including switches} - H03H 7/0115: {comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence)} - H03H 11/04: Frequency selective two-port networks - H04B 1/0057: {using diplexing or multiplexing filters for selecting the desired band} - H04B 1/48: in circuits for connecting transmitter and receiver to a common transmission path, e.g. by energy of transmitter {(H04B1/46 takes precedence)} - 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) - H04B: TRANSMISSION ## Abstract A multiplexer includes: a multilayered body including dielectric layers stacked and having first and second surfaces; a common terminal, a first terminal, a second terminal, and a ground terminal disposed on a surface of the multilayered body; a first filter disposed in the multilayered body and electrically connected between the common terminal and the first terminal; a second filter including: a first inductor electrically connected between the common terminal and the second terminal; and a second inductor connected in series with the first inductor between the first inductor and the second terminal, the second inductor at least partially overlapping with the first inductor, a capacitance between a first end of the second inductor electrically closer to the common terminal and the ground terminal being larger than a capacitance between a first end of the first inductor electrically closer to the common terminal and the ground terminal. ## Claims ### Claim 1 A multiplexer comprising: a multilayered body including a plurality of dielectric layers stacked in a vertical staking direction; a common terminal, a first terminal, a second terminal, and a ground terminal that are disposed on a surface of the multilayered body; a first filter constructed within the multilayered body and electrically connected between the common terminal and the first terminal; and a second filter constructed within the multilayered body, including: a first inductor constructed within the multilayered body, disposed in an electrical path connecting the common terminal to the second terminal, and a second inductor constructed within the multilayered body, connected in series with the first inductor along said electrical path between the first inductor and the second terminal, at least a part of the second inductor overlapping with at least a part of the first inductor in the stacking direction, a capacitance formed between a first end of the second inductor connected to the first inductor and the ground terminal being larger than a capacitance formed between a first end of the first inductor that is closer to the common terminal along said electrical path and the ground terminal. ### Claim 2 (depends on 1) The multiplexer according to claim 1, wherein at least one of the capacitance formed between the first end of the second inductor and the ground terminal and the capacitance formed between the first end of the first inductor and the ground terminal is generated by a capacitor having two opposing capacitor electrodes sandwiching one or more of the dielectric layers in between and electrically connected between the ground terminal and the first end of the second inductor or the first end of the first inductor, and wherein the capacitor is formed below the first inductor in the multilayered body, and the second inductor is disposed above the first inductor. ### Claim 3 (depends on 2) The multiplexer according to claim 2, wherein the capacitance formed between the first end of the second inductor and the ground terminal is generated by said capacitor having the two opposing capacitor electrodes sandwiching said one or more of the dielectric layers in between and electrically connected between the first end of the second inductor and the ground terminal. ### Claim 4 (depends on 3) The multiplexer according to claim 3, wherein the first inductor and the second inductor each have one of a spiral shape and a helical shape, and wherein a winding direction of the first inductor from the first end thereof to an opposite end of the first inductor is the same as a winding direction of the second inductor from the first end thereof to an opposite end of the second inductor. ### Claim 5 (depends on 3) The multiplexer according to claim 3, wherein the surface of the multilayered body on which the common terminal, the first terminal, the second terminal, and the ground terminal are disposed is a bottom surface of the multilayered body. ### Claim 6 (depends on 2) The multiplexer according to claim 2, wherein no shield electrode is interposed between a top surface of the multilayered body and the second inductor. ### Claim 7 (depends on 1) The multiplexer according to claim 1, wherein the first filter is one of a high-pass filter and a bandpass filter, and the second filter is a low-pass filter of which a passband is lower than a passband of the first filter. ### Claim 8 A filter comprising: a multilayered body including a plurality of dielectric layers stacked in a vertical stacking direction; a first signal terminal, a second signal terminal, and a ground terminal that are disposed on a surface of the multilayered body, the first signal terminal being to be electrically connected to an antenna; a first inductor constructed within the multilayered body, disposed in an electrical path connecting the first signal terminal to the second signal terminal; and a second inductor constructed within the multilayered body, connected in series with the first inductor along said electrical path between the first inductor and the second signal terminal, at least a part of the second inductor overlapping with at least a part of the first inductor in the stacking direction, a capacitance formed between a first end of the second inductor connected to the first inductor and the ground terminal being larger than a capacitance formed between a first end of the first inductor that is closer to the first signal terminal along said electrical path and the ground terminal. ### Claim 9 (depends on 8) The filter according to claim 8, wherein at least one of the capacitance formed between the first end of the second inductor and the ground terminal and the capacitance formed between the first end of the first inductor and the ground terminal is generated by a capacitor having two opposing capacitor electrodes sandwiching one or more of the dielectric layers in between and electrically connected between the ground terminal and the first end of the second inductor or the first end of the first inductor, and wherein the capacitor is formed below the first inductor in the multilayered body, and the second inductor is disposed above the first inductor. ### Claim 10 (depends on 9) The filter according to claim 9, wherein the capacitance formed between the first end of the second inductor and the ground terminal is generated by said capacitor having the two opposing capacitor electrodes sandwiching said one or more of the dielectric layers in between and electrically connected between the first end of the second inductor and the ground terminal. ### Claim 11 (depends on 9) The filter according to claim 9, wherein the surface of the multilayered body on which the common terminal, the first terminal, the second terminal, and the ground terminal are disposed is a bottom surface of the multilayered body. ### Claim 12 A multiplexer comprising: a multilayered body including a plurality of dielectric layers each having a conductive pattern or patters thereon, stacked in a vertical staking direction; a common terminal, a first terminal, a second terminal, and a ground terminal that are disposed on a bottom surface of the multilayered body; a first filter constructed of a set of the conductive patterns on the plurality of dielectric layers in the multilayered body and electrically connected between the common terminal and the first terminal; and a second filter constructed of another set of the conductive patterns on the plurality of dielectric layers in the multilayered body, the second filter including: a first inductor formed in the multilayered body, one end of the first inductor being connected to the common terminal; a second inductor formed in the multilayered body having one end thereof connected to another end of the first inductor so as to be connected in series with the first inductor, another end of the second inductor being connected to the second terminal, the second inductor being formed in a layer or layers that are above a layer or layers in which the first inductor is formed such that the second inductor at least partially overlaps with the first inductor in a plan view; and a capacitor formed in the multilayered body, connected between the ground terminal and a node that connects the first inductor and the second inductor in series, the capacitor being formed in layers that are below the layer or layers in which the first inductor is formed, and having a capacitance that is greater than a capacitance formed between the ground terminal and said one end of the first inductor connected to the common terminal, said capacitance formed between the ground terminal and said one end of the first inductor being formed only by a parasitic capacitance formed within the multilayered body, or formed by another capacitor physically formed within the multilayered body, connected between the ground terminal and said one end of the first inductor. ### Claim 13 (depends on 1) A communication module, comprising: a multiplexer according to claim 1; and a shield electrode provided above the second surface, one of an air gap and an insulator being interposed between the shield electrode and a top surface of the multilayered body, the insulator being made of a material different from a material of the multilayered body.