# US 10,320,357 B2 · Electromagnetic tunable filter systems, devices, and methods in a wireless communication network for supporting multiple frequency bands > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,357 B2 - Document ID: US10320357B2 - Status: Granted - Kind: B2 - Application number: 15/402,982 - Filed: 2017-01-10 - Published: 2017-08-24 - Granted: 2019-06-11 - Earliest claimed: 2013-03-15 - Assignees: Wispry, Inc. - Applicants: Wispry, Inc. - Inventors: Jorgen Bojer; Peter Dam Madsen; Arthur S. Morris - Web page: https://patentgrep.com/patent/US10320357B2 ## CPC - H03H 7/0153: {Electrical filters; Controlling thereof} - H03H 7/0115: {comprising only inductors and capacitors (H03H7/075, H03H7/09, H03H7/12, H03H7/13 take precedence)} - H03H 7/175: {Series LC in series path (H03H7/1783 takes precedence)} - H03H 7/1758: {Series LC in shunt or branch path (H03H7/1791 takes precedence)} - H03H 7/1766: {Parallel LC in series path (H03H7/1783 takes precedence)} - H03H 2007/013: {Notch or bandstop filters} - H03H 2210/012: Centre frequency; Cut-off frequency - H03H 2210/025: Capacitor - H03H 2210/033: Continuous - H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P) ## Abstract Systems, devices, and methods for tunable filters that are configured to support multiple frequency bands, such as within the field of cellular radio communication, can include a first resonator and a second resonator configured to block signals within one or more frequency ranges, and one or more coupling element connected to both the first resonator and the second resonator. The one or more coupling element can be configured to provide low insertion loss within a pass band. ## Claims ### Claim 1 An adaptive filter having an input node and an output node, the adaptive filter comprising: a first resonator circuit connected between the input node and a signal node; a second resonator circuit connected between the signal node and the output node; and one or more impedance coupling elements connected between the signal node and a ground; wherein the first resonator circuit and the second resonator circuit are selectively tunable to define a reject band configured to block signals having frequencies within a first signal band between the input node and the output node; and wherein the one or more impedance coupling elements are selectively tunable to define a pass band configured to pass signals having frequencies within a second signal band between the input node and the output node, wherein the one or more impedance coupling elements are tunable both to a first mode at which a coupling impedance of the one or more impedance coupling elements is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are less than frequencies within the reject band and to a second mode at which the coupling impedance of the one or more impedance coupling elements is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are greater than frequencies within the reject band. ### Claim 2 (depends on 1) The tunable filter of claim 1, wherein the one or more impedance coupling elements comprise one or more capacitors. ### Claim 3 (depends on 2) The tunable filter of claim 2, wherein the one or more impedance coupling elements comprise one or more inductors connected in a series arrangement with the one or more capacitors. ### Claim 4 (depends on 2) The tunable filter of claim 2, wherein the one or more impedance coupling elements comprise one or more inductors connected in a parallel arrangement with the one or more capacitors. ### Claim 5 (depends on 1) The tunable filter of claim 1, wherein one or more of the first resonator circuit, the second resonator circuit, or the one or more impedance coupling element is electrically tunable. ### Claim 6 (depends on 5) The tunable filter of claim 5, wherein the one or more of the first resonator circuit, the second resonator circuit, or the one or more impedance coupling element comprises a variable or switchable capacitor. ### Claim 7 (depends on 6) The tunable filter of claim 6, wherein the variable or switchable capacitor comprises one or more of a ferroelectric, paraelectric, micro-electro-mechanical systems, or solid-state capacitor. ### Claim 8 (depends on 1) The tunable filter of claim 1, wherein one or both of the first resonator circuit or the second resonator circuit comprises an inductor and a capacitor. ### Claim 9 (depends on 8) The tunable filter of claim 8, wherein the inductor and the capacitor are connected in a parallel arrangement. ### Claim 10 (depends on 1) The tunable filter of claim 1, wherein one or more of conductor traces or inductors of the first resonator circuit and the second resonator circuit are arranged at an angle of between 45 degrees and 135 degrees. ### Claim 11 (depends on 1) The tunable filter of claim 1, wherein the first resonator circuit, the second resonator circuit, and the one or more impedance coupling element are configured such that loss in the pass band is less than 5 decibels and blocking isolation in the first resonator and the second resonator is greater than 15 decibels. ### Claim 12 A method for adjusting a tunable filter, the method comprising: connecting a first resonator between an input node and a signal node, wherein the first resonator is electrically tunable; connecting a second resonator between the signal node and an output node, wherein the second resonator is electrically tunable; connecting one or more coupling element between the signal node and a ground, wherein the one or more coupling element is electrically tunable; selectively adjusting a tuning setting of one or more of the first resonator or the second resonator to define a reject band configured to block signals having frequencies within a first signal band between the input node and the output node; and selectively adjusting a tuning setting of the one or more coupling element to define a pass band configured to pass signals having frequencies within a second signal band between the input node and the output node; wherein selective adjusting a tuning setting of the one or more coupling elements comprises selectively tuning the one or more coupling elements among a first mode at which a coupling impedance of the one or more coupling elements is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are less than frequencies within the reject band and a second mode at which the coupling impedance of the one or more coupling elements is tuned such that the pass band has a minimum pass band insertion loss at frequencies that are greater than frequencies within the reject band. ### Claim 13 (depends on 12) The method of claim 12, wherein selectively adjusting a tuning setting of one or more of the first resonator or the second resonator to block signals within one or more frequency ranges comprises selectively adjusting a tuning setting of one or more of the first resonator or the second resonator to provide blocking isolation in the first resonator and the second resonator greater than 15 decibels. ### Claim 14 (depends on 12) The method of claim 12, wherein selectively adjusting a tuning setting of one or more of the first resonator or the second resonator comprises varying an electric field or current to the first resonator or the second resonator. ### Claim 15 (depends on 12) The method of claim 12, wherein selectively adjusting a tuning setting of the one or more coupling elements comprises selectively adjusting a tuning setting of the one or more coupling element to provide loss in the pass band is less than 5 decibels. ### Claim 16 (depends on 12) The method of claim 12, wherein selectively adjusting a tuning setting of the one or more coupling elements comprises selectively adjusting a tuning setting of the one or more coupling element to provide a simultaneous conjugate match to a first impedance at the first resonator and to a second impedance at the second resonator. ### Claim 17 (depends on 12) The method of claim 12, wherein selectively adjusting a tuning setting of one or more coupling element comprises varying an electric field or current to the one or more coupling element.