# US 2019/0379338 A1 · Injection lock power amplifier with back-gate bias > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0379338 A1 - Document ID: US20190379338A1 - Status: Published application - Kind: A1 - Application number: 16/550,385 - Filed: 2019-08-26 - Published: 2019-12-12 - Earliest claimed: 2018-03-23 - Assignees: Globalfoundries Inc. - Applicants: Globalfoundries Inc. - Inventors: See T. Lee; Abdellatif Bellaouar - Web page: https://patentgrep.com/patent/US20190379338A1 ## CPC - H03B 5/12: active element in amplifier being semiconductor device (H03B5/14 takes precedence) - H03F 1/565: {using inductive elements} - H03B 5/1212: {the amplifier comprising a pair of transistors, wherein an output terminal of each being connected to an input terminal of the other, e.g. a cross coupled pair} - H03B 5/1228: {the amplifier comprising one or more field effect transistors} - H03F 3/193: with field-effect devices (H03F3/195 takes precedence) - H03F 3/245: {with semiconductor devices only} - H03F 3/45183: {Long tailed pairs (H03F3/4521, H03F3/45237 take precedence)} - H03B 2200/0074: Locking of an oscillator by injecting an input signal directly into the oscillator - H03F 3/195: in integrated circuits - H03F 3/26: Push-pull amplifiers; Phase-splitters therefor (duplicated single-ended push-pull arrangements or phase-splitters therefor H03F3/30) - H03F 2200/541: Transformer coupled at the output of an amplifier - H03F 2203/45318: the AAC comprising a cross coupling circuit, e.g. two extra transistors cross coupled - H03F 2203/45481: the CSC comprising only a direct connection to the supply voltage, no other components being present - H03F 2203/45621: the IC comprising a transformer for phase splitting the input signal - H03F 2203/45731: the LC comprising a transformer - H03B: GENERATION OF OSCILLATIONS, DIRECTLY OR BY FREQUENCY-CHANGING, BY CIRCUITS EMPLOYING ACTIVE ELEMENTS WHICH OPERATE IN A NON-SWITCHING MANNER; GENERATION OF NOISE BY SUCH CIRCUITS (generators adapted for electrophonic musical instruments G10H; masers or lasers H01S; generation of oscillations in plasma H05H) - H03F: AMPLIFIERS ## Abstract In an exemplary structure, a transformer has a primary side and a secondary side. Output from the primary side is coupled to the secondary side. A first power supply is connected to a center tap of the primary side of the transformer. An oscillator includes a first transistor and a second transistor. The front-gate of the first transistor is connected to the drain of the second transistor and the primary side of the transformer. The front-gate of the second transistor is connected to the drain of the first transistor and the primary side of the transformer. A third transistor is connected to the first transistor and a fourth transistor is connected to the second transistor. The third and fourth transistors inject a desired frequency to the oscillator. A voltage source is connected to the back-gate of the first transistor and the back-gate of the second transistor. ## Claims ### Claim 1 A structure, comprising: a transformer having a primary side and a secondary side; a power supply connected to a center tap of the primary side of the transformer; an oscillator comprising a pair of switching transistors connected to each end of the primary side of the transformer; a pair of injection transistors connected to the switching transistors; and a voltage source connected to each transistor of the pair of switching transistors of the oscillator, wherein each transistor of the pair of switching transistors of the oscillator and each transistor of the pair of injection transistors has a front-gate node and a back-gate node. ### Claim 2 (depends on 1) The structure according to claim 1, wherein the front-gate node of each transistor of the pair of switching transistors is connected to each end of the primary side of the transformer. ### Claim 3 (depends on 1) The structure according to claim 1, wherein the back-gate node of each transistor of the pair of switching transistors is connected to the voltage source, and wherein output power from the secondary side of the transformer is controlled by adjusting the voltage source connected to the back-gate node of the switching transistors. ### Claim 4 (depends on 3) The structure according to claim 3, wherein the voltage source connected to the back-gate node of the switching transistors is adjusted independently for each transistor of the pair of switching transistors. ### Claim 5 (depends on 1) The structure according to claim 1, wherein the injection transistors inject a desired frequency to the oscillator. ### Claim 6 (depends on 5) The structure according to claim 5, wherein the frequency is tuned by adjusting the voltage source to the back-gate node of the switching transistors. ### Claim 7 (depends on 1) The structure according to claim 1, wherein each transistor of the pair of switching transistors and each transistor of the pair of injection transistors comprises a fully-depleted semiconductor-on-insulator (FDSOI) transistor. ### Claim 8 (depends on 1) The structure according to claim 1, wherein the secondary side of the transformer is configured for single ended output having one end of the secondary side of the transformer connected to ground. ### Claim 9 (depends on 1) The structure according to claim 1, further comprising: an input transformer having a primary side and a secondary side, wherein the primary side of the input transformer has an RF input; and each end of the secondary side of the input transformer is connected to a front-gate of one of the transistors of the pair of injection transistors. ### Claim 10 (depends on 9) The structure according to claim 9, further comprising: a DC power supply connected to a center tap of the secondary side of the input transformer. ### Claim 11 (depends on 10) The structure according to claim 10, wherein the DC power supply provides voltage for the pair of injection transistors. ### Claim 12 A power amplifier, comprising: a transformer having a primary side and a secondary side; a power supply connected to a center tap of the primary side of the transformer; a pair of cross-coupled switching transistors connected to each end of the primary side of the transformer; and a pair of injection transistors connected to the cross-coupled switching transistors, wherein each transistor of the pair of switching transistors and each transistor of the pair of injection transistors has a front-gate node and a back-gate node, and wherein an injection signal source is connected to the front-gate node of each transistor of the pair of injection transistors, and a bias voltage source is connected to the back-gate node of each transistor of the pair of switching transistors. ### Claim 13 (depends on 12) The power amplifier according to claim 12, wherein the front-gate node of each transistor of the pair of switching transistors is connected to each end of the primary side of the transformer. ### Claim 14 (depends on 12) The power amplifier according to claim 12, wherein output power from the secondary side of the transformer is controlled by adjusting a bias voltage connected to the back-gate node of each transistor of the pair of switching transistors. ### Claim 15 (depends on 12) The power amplifier according to claim 12, wherein a separate bias voltage source is connected to the back-gate node of each transistor of the pair of switching transistors, each separate bias voltage source being adjusted independently. ### Claim 16 (depends on 12) The power amplifier according to claim 12, wherein the injection transistors inject a desired frequency to the switching transistors. ### Claim 17 (depends on 16) The power amplifier according to claim 16, wherein the frequency is tuned by adjusting a voltage source to the back-gate node of the switching transistors. ### Claim 18 (depends on 12) The power amplifier according to claim 12, wherein each transistor of the pair of switching transistors and each transistor of the pair of injection transistors comprises a fully-depleted semiconductor-on-insulator (FDSOI) transistor. ### Claim 19 (depends on 12) The power amplifier according to claim 12, further comprising: an input transformer having a primary side and a secondary side, wherein the primary side of the input transformer has an RF input; and each end of the secondary side of the input transformer is connected to the front-gate node of one of the transistors of the pair of injection transistors. ### Claim 20 A method of controlling a power amplifier, comprising: cross coupling a pair of switching transistors connected to the primary side of a transformer having a primary side and a secondary side; providing an injection current to each transistor of the pair of switching transistors, wherein the injection current determines a desired frequency for the switching transistors to oscillate the transformer; measuring output power from the secondary side of the transformer; determining if output power from both ends of the secondary side of the transformer are approximately equal; and responsive to the output power from both ends of the secondary side of the transformer not being approximately equal, controlling output power of the switching transistors by adjusting voltage to a back-gate of the switching transistors.