# US 8,149,903 B2 · Systems and methods for ramping power amplifier output power > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,149,903 B2 - Document ID: US8149903B2 - Status: Granted - Kind: B2 - Application number: 12/652,265 - Filed: 2010-01-05 - Published: 2010-04-29 - Granted: 2012-04-03 - Earliest claimed: 2003-04-18 - Assignees: Broadcom Corporation - Inventors: Chris Nilson - Web page: https://patentgrep.com/patent/US8149903B2 ## CPC - H03F 3/19: with semiconductor devices only - H03F 1/0205: {in transistor amplifiers} - H03F 1/0261: {with control of the polarisation voltage or current, e.g. gliding Class A} - H03F 1/223: {with MOSFET's} - H03F 3/24: of transmitter output stages - H03G 1/0023: {in emitter-coupled or cascode amplifiers (H03G1/0029 takes precedence)} - H03G 3/004: {Control by varying the supply voltage} - H03F 2200/18: the bias of the gate of a FET being controlled by a control signal - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F: AMPLIFIERS - H03G: CONTROL OF AMPLIFICATION ## Abstract A power amplifier circuit including a first transistor, a second transistor, and a power control circuit. The first transistor includes a first input and a first output. The second transistor includes a second input coupled in series with the first output of the first transistor. The input circuit is coupled to the first input of the first transistor. The power control circuit is coupled to the second input of the second transistor. The control circuit includes a time delay circuit and a variable source. ## Claims ### Claim 1 A transceiver, comprising: a transmitter configured to transmit a data transmission at a power output level; and a power control circuit configured to adjust the power output level over time using a ramp shape, the ramp shape being characterized by a first mathematical function having a plurality of steps, each of the plurality of steps being combined with a corresponding second mathematical function from a plurality of second mathematical functions, each of the plurality of second mathematical functions being equivalent. ### Claim 2 (depends on 1) The transceiver of claim 1, wherein the transmitter comprises: a first transistor configured to amplify an input data signal to provide the data transmission; and a second transistor, coupled to the power control circuit, configured to control an envelope of the data transmission using the ramp shape. ### Claim 3 (depends on 1) The transceiver of claim 1, wherein the power control circuit comprises: a digitally controlled variable current source configured to convert a digital control word to an analog voltage level, the analog voltage level being characterized by the first mathematical function; and a series network, including a resistor and a capacitor, configured to shape the analog voltage level by the corresponding second mathematical function to provide the ramp shape. ### Claim 4 (depends on 1) The transceiver of claim 1, wherein the plurality of second mathematical functions includes at least one selected from a group consisting of: a linear ramp, a step ramp, and an exponential ramp signal. ### Claim 5 (depends on 1) The transceiver of claim 1, wherein the transmitter is configured to transmit the data transmission at the power output level to a receiver. ### Claim 6 (depends on 1) The transceiver of claim 1, wherein the transmitter is configured to transmit the data transmission over a wireless data link. ### Claim 7 (depends on 6) The transceiver of claim 6, wherein the transmitter is configured to transmit the data transmission over a single channel of the wireless data link, the single channel of the wireless data link being from a plurality of channels that are useable by the transceiver. ### Claim 8 (depends on 1) The transceiver of claim 1, wherein the transmitter is configured to transmit the data transmission in accordance with a communication protocol. ### Claim 9 (depends on 8) The transceiver of claim 8, wherein the communication protocol is selected from a group consisting of: a Bluetooth specification; and an IEEE 802.11 specification. ### Claim 10 (depends on 1) The transceiver of claim 1, wherein the transmitter is configured to transmit the data transmission during a first time slot of a plurality of time slots. ### Claim 11 (depends on 1) The transceiver of claim 1, further comprising: a receiver configured to receive a second data transmission at a second power output level. ### Claim 12 A method for adjusting a power output level of a data transmission, comprising: (a) adjusting the power output level over time using a ramp shape, the ramp shape being characterized by a first mathematical function having a plurality of steps, each of the plurality of steps being combined with a corresponding second mathematical function from a plurality of second mathematical functions, each of the plurality of second mathematical functions being equivalent; and (b) transmitting the data transmission at the power output level. ### Claim 13 (depends on 12) The method of claim 12, wherein step (b) comprises: (b)(i) amplifying an input data signal using a first transistor to provide the data transmission; and (b)(ii) controlling an envelope of the data transmission with a second transistor using the ramp shape. ### Claim 14 (depends on 12) The method of claim 12, wherein step (a) comprises: (a)(i) converting a digital control word to an analog voltage level, the analog voltage level being characterized by the first mathematical function; and (a)(ii) shaping the analog voltage level by the corresponding second mathematical function to provide the ramp shape. ### Claim 15 (depends on 12) The method of claim 12, wherein the plurality of second mathematical functions includes at least one selected from a group consisting of: a linear ramp, a step ramp, and an exponential ramp signal. ### Claim 16 (depends on 12) The method of claim 12, wherein step (b) comprises: (b)(i) transmitting the data transmission at the power output level to a receiver. ### Claim 17 (depends on 12) The method of claim 12, wherein step (b) comprises: (b)(i) transmitting the data transmission at the power output level over a wireless data link. ### Claim 18 (depends on 17) The method of claim 17, wherein step (b)(i) comprises: (b)(i)(A) transmitting the data transmission at the power output level over a single channel of the wireless data link, the single channel of the wireless data link being from a plurality of channels that are useable by the transceiver. ### Claim 19 (depends on 12) The method of claim 12, wherein step (b) comprises: (b)(i) transmitting the data transmission at the power output level in accordance with a communication protocol. ### Claim 20 (depends on 19) The method of claim 19, wherein the communication protocol is selected from a group consisting of: a Bluetooth specification; and an IEEE 802.11 specification. ### Claim 21 (depends on 12) The method of claim 12, wherein step (b) comprises: (b)(i) transmitting the data transmission at the power output level during a first time slot of a plurality of time slots. ### Claim 22 (depends on 12) The method of claim 12, further comprising: (c) receiving a second data transmission at a second power output level. ### Claim 23 (depends on 1) The transceiver of claim 1, wherein the power control circuit is further configured to increase the power output level over time. ### Claim 24 (depends on 12) The method of claim 12, wherein step (a) comprises: (a)(i) increasing the power output level over time.