Li Liu

US Patent:

6989712, Jan 24, 2006

Filed:

Mar 17, 2004

Appl. No.:

10/803850

Inventors:

Li Liu - Littleton MA, US
Christopher C. Souchuns - Ashland MA, US
Ping Li - Dunstable MA, US
Gregory N. Henderson - Sudbury MA, US

Assignee:

TriQuint Semiconductor, Inc. - Hillsboro OR

International Classification:

H03G 3/20

US Classification:

330133, 330140

Abstract:

A multi-stage amplifier is coupled with a power detector. The multi-stage amplifier includes a plurality of amplifier stages in series, with a signal path extending through them. The power detector is coupled to an interior node of the amplifier along the signal path, and is operable to sample a first signal being transmitted on the signal path. The power detector outputs a second signal reflective of a power of the first signal. In one embodiment, the interior node is in a matching network of the amplifier disposed between a first amplifier stage and a final amplifier stage of the amplifier. The second signal may be used in a feedback network to adjust an amount of amplification of the first signal by the amplifier.

US Patent:

7010284, Mar 7, 2006

Filed:

Jun 10, 2003

Appl. No.:

10/459239

Inventors:

Li Liu - Littleton MA, US
Christopher C. Souchuns - Ashland MA, US
Ping Li - Dunstable MA, US
Gregory N. Henderson - Sudbury MA, US

Assignee:

TriQuint Semiconductor, Inc. - Hillsboro OR

International Classification:

H04B 1/06

US Classification:

4552532, 4551271, 4552511, 4552461, 330 99, 330103, 330133, 330140

Abstract:

A multi-stage amplifier is coupled with a power detector. The multi-stage amplifier includes a plurality of amplifier stages in series, with a signal path extending through them. The power detector is coupled to an interior node of the amplifier along the signal path, and is operable to sample a first signal being transmitted on the signal path. The power detector outputs a second signal reflective of a power of the first signal. In one embodiment, the interior node is in a matching network of the amplifier disposed between a first amplifier stage and a final amplifier stage of the amplifier. The second signal may be used in a feedback network to adjust an amount of amplification of the first signal by the amplifier.

US Patent:

20040070454, Apr 15, 2004

Filed:

Jun 27, 2003

Appl. No.:

10/607959

Inventors:

Gregory Henderson - Sudbury MA, US
Christopher Souchuns - Ashland MA, US
Li Liu - Littleton MA, US
Ping Li - Dunstable MA, US
On San Andy Tang - Merrimack NH, US
Ashley Imhoff - Boxford MA, US

Assignee:

TriQuint Semiconductor, Inc.

International Classification:

H03G003/10

US Classification:

330/285000

Abstract:

An amplifier and a bias circuit are disclosed. The bias circuit receives an analog voltage signal that reflects a desired output power level of the amplifier. The bias circuit causes the amplifier to draw a quiescent current, from a fixed-level DC voltage supply, that varies proportionally with the analog voltage signal. In this way, the current consumption of the amplifier is optimized for the desired output power level, while maintaining a desired, high degree of linearity. The amplifier and bias circuit may be in a wireless communications device that includes a baseband processor. The baseband processor generates the analog voltage signal, and a data signal that is converted to a RF signal. The RF signal is amplified by a preamplifier to a power level determined by the analog voltage signal. The RF signal is output to the amplifier for further amplification, and subsequently is broadcast through an antenna.

US Patent:

20040072554, Apr 15, 2004

Filed:

Sep 11, 2003

Appl. No.:

10/661787

Inventors:

Gregory Henderson - Sudbury MA, US
Christopher Souchuns - Ashland MA, US
Li Liu - Littleton MA, US
Ping Li - Dunstable MA, US
On San Andy Tang - Merrimack NH, US
Ashley Imhoff - Boxford MA, US

Assignee:

TriQuint Semiconductor, Inc.

International Classification:

H04B001/16

US Classification:

455/341000

Abstract:

An automatic-bias amplifier circuit includes an amplifier having an input, an output, and a signal path between the input and output. A power detector is coupled for sampling the power of a signal passed on the signal path. The point of coupling may be the output and/or at one or more internal nodes of the amplifier. The power detector outputs an analog voltage signal reflective of the power of the signal to a bias circuit. The bias circuit causes the amplifier to draw a quiescent current, from a fixed level DC power supply, that varies in proportion to the analog voltage signal. Accordingly, the power consumption of the amplifier is optimized for all output power levels of the amplifier, while maintaining a desired degree of linearity. The automatic-bias amplifier circuit may be used in a wireless radio frequency communications device, e.g., a cellular phone.