# US 10,320,341 B2 · Amplifier > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,320,341 B2 - Document ID: US10320341B2 - Status: Granted - Kind: B2 - Application number: 15/316,562 - Filed: 2016-05-02 - Published: 2018-07-05 - Granted: 2019-06-11 - Earliest claimed: 2016-05-02 - Assignees: Telefonaktiebolaget LM Ericsson (publ) - Applicants: Telefonaktiebolaget LM Ericsson (publ) - Inventors: Fenghao Mu - Web page: https://patentgrep.com/patent/US10320341B2 ## CPC - H03F 1/342: {in field-effect transistor amplifiers} - H03F 3/195: in integrated circuits - H03F 3/45179: {using MOSFET transistors as the active amplifying circuit (H03F3/45278 takes precedence)} - H04B 1/1638: {Special circuits to enhance selectivity of receivers not otherwise provided for (resonant circuits H03H)} - H04B 1/18: Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) - H03F 2200/144: the feedback circuit of the amplifier stage comprising a passive resistor and passive capacitor - H03F 2200/21: Bias resistors are added at the input of an amplifier - H03F 2200/222: A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier - H03F 2200/294: the amplifier being a low noise amplifier [LNA] - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F 2200/546: A tunable capacitance being present in an amplifier circuit - H03F 2203/45024: the differential amplifier amplifying transistors are cascode coupled transistors - H03F 2203/45236: Two dif amps realised in MOS or JFET technology, one of them being of the p-channel type and the other one of the n-channel type, are coupled in parallel with their gates - H03F 2203/45241: Two dif amps realised in MOS or JFET technology, the dif amps being either both of the p-channel type or both of the n-channel type, are coupled in parallel with their gates - H03F 2203/45512: the FBC comprising one or more capacitors, not being switched capacitors, and being coupled between the LC and the IC - H03F 2203/45524: the FBC comprising one or more active resistors and being coupled between the LC and the IC - H03F 2203/45526: the FBC comprising a resistor-capacitor combination and being coupled between the LC and the IC - H04B 1/0053: {with common antenna for more than one band} - H04B 1/0082: {with a common local oscillator for more than one band} - H03F: AMPLIFIERS - H04B: TRANSMISSION ## Abstract An amplifier for a receiver circuit is disclosed. The amplifier has an input node (Vin) and an output node (Vout). It comprises a tunable tank circuit connected to the output node (Vout), a feedback circuit path connected between the output node (Vout) and the input node (Vin), and a tunable capacitor connected between an internal node of the feedback circuit path and a reference-voltage node. A receiver circuit and a communication apparatus is disclosed as well. ## Claims ### Claim 1 An amplifier for a receiver circuit, the amplifier having an input node (Vin) and an output node (Vout), comprising a tunable tank circuit connected to the output node (Vout); a feedback circuit path connected between the output node (Vout) and the input node (Vin); and a tunable capacitor connected between an internal node of the feedback circuit path and a reference-voltage node, wherein the feedback circuit path comprises a series connection of at least one resistor and at least one capacitor. ### Claim 2 (depends on 1) The amplifier according to claim 1, wherein the feedback circuit path is a passive circuit. ### Claim 3 (depends on 1) The amplifier according to claim 1, wherein the at least one resistor is tunable. ### Claim 4 (depends on 1) The amplifier according to claim 1, wherein said at least one capacitor comprises a first capacitor, said at least one resistor comprises a first resistor connected between the output node (Vout) and the first capacitor and a second resistor connected between the first capacitor and the input node (Vin). ### Claim 5 (depends on 4) The amplifier according to claim 4, wherein the internal node is a node between the first capacitor and the second resistor. ### Claim 6 (depends on 1) The amplifier according to claim 1, comprising a first transistor in common-source configuration. ### Claim 7 (depends on 6) The amplifier according to claim 6, comprising a second transistor connected in a cascode configuration between the first transistor and the output node (Vout). ### Claim 8 (depends on 1) A differential amplifier for a receiver circuit, comprising a first and a second amplifier, each according to claim 1. ### Claim 9 (depends on 1) A receiver circuit comprising an amplifier according to claim 1. ### Claim 10 (depends on 9) A communication apparatus comprising the receiver circuit according to claim 9. ### Claim 11 (depends on 10) The communication apparatus according to claim 10, wherein the communication apparatus is a wireless communication device for a cellular communication network. ### Claim 12 (depends on 10) The communication apparatus according to claim 10, wherein the communication apparatus is a radio base station for a cellular communication network. ### Claim 13 (depends on 8) A receiver circuit comprising the differential amplifier of claim 8. ### Claim 14 (depends on 13) A communication apparatus comprising the receiver circuit according to claim 13. ### Claim 15 (depends on 14) The communication apparatus according to claim 14, wherein the communication apparatus is a wireless communication device for a cellular communication network. ### Claim 16 (depends on 14) The communication apparatus according to claim 14, wherein the communication apparatus is a radio base station for a cellular communication network.