# US 2017/0288796 A1 · Variable gain power amplifiers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2017/0288796 A1 - Document ID: US20170288796A1 - Status: Published application - Kind: A1 - Application number: 15/627,249 - Filed: 2017-06-19 - Published: 2017-10-05 - Earliest claimed: 2015-06-30 - Assignees: Texas Instruments Incorporated - Applicants: Texas Instruments Incorporated - Inventors: Sudipto Chakraborty - Web page: https://patentgrep.com/patent/US20170288796A1 ## CPC - 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} - H03B 5/1265: {switched capacitors} - H03F 1/0211: {with control of the supply voltage or current} - H03F 1/0277: {Selecting one or more amplifiers from a plurality of amplifiers} - H03F 3/193: with field-effect devices (H03F3/195 takes precedence) - H03F 3/211: {using a combination of several amplifiers (H03F3/60 takes precedence)} - H03F 3/213: in integrated circuits - H03F 3/245: {with semiconductor devices only} - H03F 3/45: Differential amplifiers (differential sense amplifiers G11C7/062) - H03G 1/0005: {Circuits characterised by the type of controlling devices operated by a controlling current or voltage signal} - H03G 3/004: {Control by varying the supply voltage} - H03G 3/3042: {in modulators, frequency-changers, transmitters or power amplifiers} - H04B 2001/0416: {having gain or transmission power control} - 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 - H03G: CONTROL OF AMPLIFICATION - H04B: TRANSMISSION ## Abstract A variable-gain power amplifying technique includes generating, with a network of one or more reactive components included in an oscillator, a first oscillating signal, and outputting, via one or more taps included in the network of the reactive components, a second oscillating signal. The second oscillating signal has a magnitude that is proportional to and less than the first oscillating signal. The power amplifying technique further includes selecting one of the first and second oscillating signals to use for generating a power-amplified output signal, and amplifying the selected one of the first and second oscillating signals to generate the power-amplified output signal. ## Claims ### Claim 1 An integrated circuit comprising: an oscillator having: a first node, a second node, a network of one or more reactive components coupled between the first node and the second node, the network of the reactive components having at least one tap between the first and second nodes, a first output coupled to the network of the reactive components via the second node, and a second output coupled to the network of the reactive components via the tap; and a power amplifier having: a first input coupled to the first output of the oscillator, a second input coupled to the second output of the oscillator, and an output. ### Claim 2 (depends on 1) The integrated circuit of claim 1, wherein the tap is a first tap, wherein the network of the reactive components has a second tap located between the first and second nodes, wherein the first output of the oscillator is a first differential output having a first terminal coupled to the network of the reactive components via the first node, and a second terminal coupled to the network of the reactive components via the second node, and wherein the second output of the oscillator is a second differential output having a first terminal coupled to the network of the reactive components via the first tap, and a second terminal coupled to the network of the reactive components via the second tap. ### Claim 3 (depends on 2) The integrated circuit of claim 2, wherein the network of the reactive components includes one or more inductors coupled in series between the first and second nodes of the oscillator, wherein the first and second taps are coupled to the one or more inductors, and wherein an inductance between the first and second terminals of the first differential output of the oscillator is greater than an inductance between the first and second terminals of the second differential output of the oscillator. ### Claim 4 (depends on 2) The integrated circuit of claim 2, wherein the network of the reactive components includes one or more capacitors coupled in series between the first and second nodes of the oscillator, wherein the first and second taps are coupled to the one or more capacitors, and wherein a capacitance between the first and second terminals of the first differential output of the oscillator is greater than a capacitance between the first and second terminals of the second differential output of the oscillator. ### Claim 5 (depends on 1) The integrated circuit of claim 1, wherein the first node of the oscillator is at least one of a power rail or a ground rail for the oscillator. ### Claim 6 (depends on 5) The integrated circuit of claim 5, wherein the network of the reactive components includes one or more inductors coupled in series between the first and second nodes of the oscillator, wherein the tap is coupled to the one or more inductors, and wherein an inductance between the first node and the second node of the oscillator is greater than an inductance between the tap of the network of the reactive components and the first node of the oscillator. ### Claim 7 (depends on 5) The integrated circuit of claim 5, wherein the network of the reactive components includes one or more capacitors coupled in series between the first and second nodes of the oscillator, wherein the tap is coupled to the one or more capacitors, and wherein a capacitance between the first node and the second node of the oscillator is greater than a capacitance between the tap of the network of the reactive components and the first node of the oscillator. ### Claim 8 (depends on 1) The integrated circuit of claim 1, wherein the network of the reactive components includes one or more inductors coupled in series between the first and second nodes of the oscillator. ### Claim 9 (depends on 1) The integrated circuit of claim 1, wherein the network of the reactive components includes one or more capacitors coupled in series between the first and second nodes of the oscillator. ### Claim 10 (depends on 1) The integrated circuit of claim 1, wherein the power amplifier further includes: a first amplifier stage having an input and an output; and a second amplifier stage having an input coupled to the output of the first amplifier stage, and an output. ### Claim 11 (depends on 10) The integrated circuit of claim 10, wherein the power amplifier further includes: a first adjustable power supply coupled to the first amplifier stage; and a second adjustable power supply coupled to the second amplifier stage. ### Claim 12 (depends on 11) The integrated circuit of claim 11, wherein the first adjustable power supply is a first programmable low-dropout regulator (LDO), and wherein the second adjustable power supply is a second programmable LDO. ### Claim 13 (depends on 10) The integrated circuit of claim 10, wherein the first amplifier stage includes: a power rail; an adjustable resistance; a first self-biased inverter coupled to the power rail via the adjustable resistance; a second self-biased inverter coupled to the power rail via the adjustable resistance. ### Claim 14 (depends on 13) The integrated circuit of claim 13, wherein the power rail is coupled to an adjustable power source. ### Claim 15 (depends on 14) The integrated circuit of claim 14, wherein the adjustable power source is an adjustable low-dropout regulator (LDO). ### Claim 16 (depends on 13) The integrated circuit of claim 13, wherein the first amplifier stage further includes a second adjustable resistance, wherein the first self-biased inverter is coupled to a ground rail via the second adjustable resistance, and wherein the second self-biased inverter is coupled to the ground rail via the second adjustable resistance. ### Claim 17 (depends on 13) The integrated circuit of claim 13, wherein the first self-biased inverter includes an input, an output, and a resistor coupled between the input and the output of the first self-biased inverter, and wherein the second self-biased inverter includes an input, an output, and a resistor coupled between the input and the output of the second self-biased inverter. ### Claim 18 (depends on 10) The integrated circuit of claim 10, wherein the second amplifier stage includes: an inverter having a first transistor and a second transistor; a resistor coupled to the output of the inverter; a first bias voltage source; a second bias voltage source; a first switch coupled between the resistor and a gate of the first transistor; a second switch coupled between the first bias voltage source and the gate of the first transistor; a third switch coupled between the resistor and a gate of the second transistor; and a fourth switch coupled between the second bias voltage source and the gate of the second transistor. ### Claim 19 (depends on 18) The integrated circuit of claim 18, further including: a control unit coupled to the first, second, third, and fourth switches and configured to switch the second amplifier stage between a self-biased operating mode and a non-linear operating mode.