# US 7,612,607 B2 · Small size power amplifier with amplifiers switched > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,612,607 B2 - Document ID: US7612607B2 - Status: Granted - Kind: B2 - Application number: 11/905,857 - Filed: 2007-10-04 - Published: 2008-05-15 - Granted: 2009-11-03 - Earliest claimed: 2006-10-05 - Assignees: NEC Electronics Corporation - Inventors: Fumio Harima - Web page: https://patentgrep.com/patent/US7612607B2 ## CPC - H03F 1/0288: {using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers} - H03F: AMPLIFIERS ## Abstract A small size power amplifier includes a first amplifier provided for a first signal path; a second amplifier provided for said first signal path; and a third amplifier provided for a second signal path parallel to said first signal path. A voltage control circuit configured to bias one of a first set of said first amplifier and said second amplifier, and a second set of said third amplifier, based on an output power. ## Claims ### Claim 1 A small size power amplifier comprising: a first amplifier provided for a first signal path; a second amplifier provided for said first signal path; a third amplifier provided for a second signal path parallel to said first signal path; a voltage control circuit configured to bias one of a first set of said first amplifier and said second amplifier, and a second set of said third amplifier, based on an output power; and a node that splits the second signal path from the first signal path, said node being connected to a first matching circuit and a second matching circuit, said first matching circuit and the second matching circuit being located in the first signal path prior to said first amplifier. ### Claim 2 (depends on 1) The small size power amplifier according to claim 1, wherein said voltage control circuit biases said first set of said first amplifier and said second amplifier without biasing said second set of said third amplifier at a high output power, and biases said second set of said third amplifier without biasing said first set of said first amplifier and said second amplifier at a low output power. ### Claim 3 (depends on 1) The small size power amplifier according to claim 1, wherein said voltage control circuit biases said first set of said first amplifier and said second amplifier without biasing said second set of said third amplifier at a low output power, and biases said second set of said third amplifier without biasing said first set of said first amplifier and said second amplifier at a high output power. ### Claim 4 (depends on 1) The small size power amplifier according to claim 1, wherein a number of said amplifiers in said first signal path is more than in said second signal path. ### Claim 5 (depends on 1) The small size power amplifier according to claim 1, wherein said voltage control circuit adjusts a gain of said power amplifier such that a gain of said first signal path is equal to that of said second signal path. ### Claim 6 (depends on 1) The small size power amplifier according to claim 1, wherein the first amplifier is connected with said second matching circuit. ### Claim 7 (depends on 6) The small size power amplifier according to claim 6, further comprising a third matching circuit, wherein the third matching circuit is connected with said first amplifier. ### Claim 8 (depends on 7) The small size power amplifier according to claim 7, wherein the second amplifier is connected with said third matching circuit. ### Claim 9 (depends on 8) The small size power amplifier according to claim 8, further comprising a fourth matching circuit, wherein said fourth matching circuit is connected with said second amplifier. ### Claim 10 (depends on 9) The small size power amplifier according to claim 9, further comprising a fifth matching circuit, wherein said fifth matching circuit is connected with said node. ### Claim 11 (depends on 10) The small size power amplifier according to claim 10, wherein the third amplifier is connected with said fifth matching circuit. ### Claim 12 (depends on 11) The small size power amplifier according to claim 11, further comprising a sixth matching circuit, wherein said sixth matching circuit is connected with said third amplifier. ### Claim 13 (depends on 12) The small size power amplifier according to claim 12, further comprising another node connected with said fourth matching circuit and said sixth matching circuit. ### Claim 14 (depends on 13) The small size power amplifier according to claim 13, further comprising a seventh matching circuit, wherein said seventh matching circuit is connected with said another node. ### Claim 15 (depends on 1) The small size power amplifier according to claim 1, wherein the voltage control circuit is connected to the first signal path, in a location placed between a capacitor of the second matching circuit and the first amplifier, via a resistor. ### Claim 16 (depends on 1) The small size power amplifier according to claim 1, wherein a number of amplifiers provided in the first signal path is larger than a number of amplifiers provided in the second signal path. ### Claim 17 A small size power amplifier comprising: a first port; a first matching circuit connected with said first port; a first node connected with said first matching circuit; a second matching circuit connected with said first node; a first amplifier connected with said second matching circuit; a third matching circuit connected with said first amplifier; a second amplifier connected with said third matching circuit; a fourth matching circuit connected with said second amplifier; a fifth matching circuit connected with said first node; a third amplifier connected with said fifth matching circuit; a sixth matching circuit connected with said third amplifier; a second node connected with said fourth matching circuit and said sixth matching circuit; a seventh matching circuit connected with said second node; a second port connected with said seventh matching circuit; and a voltage control circuit configured to bias one of a set of said first and second amplifiers and a set of said third amplifier. ### Claim 18 (depends on 17) The small size power amplifier according to claim 17, wherein each of said third, fourth, sixth and seventh matching circuits includes a bias supply line. ### Claim 19 A small size power amplifier comprising: a first matching circuit; a node connected with said first matching circuit; a second matching circuit connected with said node; a first amplifier connected with said second matching circuit; a third matching circuit connected with said first amplifier; a second amplifier connected with said third matching circuit; a fourth matching circuit connected with said second amplifier; a fifth matching circuit connected with said node; a third amplifier connected with said fifth matching circuit; and a voltage control circuit configured to bias one of a set of said first and second amplifiers and a set of said third amplifier. ### Claim 20 (depends on 19) The small size power amplifier according to claim 19, wherein the voltage control circuit is connected to a first signal path, in a location placed between a capacitor of the second matching circuit and the first amplifier, via a resistor.