James X Qiu

US Patent:

8253488, Aug 28, 2012

Filed:

Jun 11, 2012

Appl. No.:

13/493854

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US

Assignee:

Maxlinear, Inc. - Carlsbad CA

International Classification:

H03F 3/20

US Classification:

330133

Abstract:

A circuit for self-calibrating a gain control system samples the output of a digital amplifier coupled in series with one or more analog amplifiers to correct errors in a discrete stepped gain control. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit.

US Patent:

8427232, Apr 23, 2013

Filed:

Aug 7, 2012

Appl. No.:

13/568865

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US

Assignee:

Maxlinear - Carlsbad CA

International Classification:

H03G 3/20

US Classification:

330133, 330279

Abstract:

A circuit for self-calibrating a gain control system samples the output of a digital amplifier coupled in series with one or more analog amplifiers to correct errors in a discrete stepped gain control. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit.

US Patent:

8442154, May 14, 2013

Filed:

Apr 23, 2010

Appl. No.:

12/799378

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US
Sheng Ye - Carlsbad CA, US
Curtis Ling - Carlsbad CA, US

Assignee:

Maxlinear, Inc. - Carlsbad CA

International Classification:

H03K 9/00

US Classification:

375316, 375340

Abstract:

A communication receiver which applies signal processing for quantitatively estimating receive signal factors such as communication channel quality, signal characteristics, and overall system received bit error rate (BER) or packet error rate (PER) and which applies a general algorithm for mapping these estimated factors to control receiver performance and minimize power consumption.

US Patent:

8472912, Jun 25, 2013

Filed:

Dec 13, 2010

Appl. No.:

12/966905

Inventors:

Sridhar Ramesh - Carlsbad CA, US
James Qiu - Carlsbad CA, US
Sugbong Kang - Carlsbad CA, US

Assignee:

MaxLinear, Inc. - Carlsbad CA

International Classification:

H04B 1/16

US Classification:

455334, 455101, 455137, 455323, 375347

Abstract:

A diversity receiver includes a first RF front end module for receiving a first RF signal, and frequency converting the first RF signal and outputting a first diversity signal, a second RF front end module for receiving a second RF signal, frequency converting the second RF signal and outputting a second diversity signal, a first converter for converting the first diversity signal to a first time-domain signal, a second converter for converting the second diversity signal to a second time-domain signal, a first transformer for translating the first time-domain signal to a first frequency-domain signal, a second transformer for translating the second time-domain signal to a second frequency-domain signal, a first pre-equalizer for equalizing the first frequency-domain signal, a second pre-equalizer for equalizing the second frequency-domain signal, and a combiner for combining the first and second pre-equalized frequency-domain signals. The diversity receiver further includes a channel estimator having a mirror window.

US Patent:

20100277240, Nov 4, 2010

Filed:

May 4, 2010

Appl. No.:

12/799870

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US

International Classification:

H03G 3/00

US Classification:

330278

Abstract:

A circuit for self-calibrating a gain control system samples the output of a digital amplifier coupled in series with one or more analog amplifiers to correct errors in a discrete stepped gain control. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit.

US Patent:

20130214857, Aug 22, 2013

Filed:

Mar 18, 2013

Appl. No.:

13/845348

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US

International Classification:

H03G 3/20

US Classification:

330 98

Abstract:

A circuit for self-calibrating a gain control system samples the output of a digital amplifier coupled in series with one or more analog amplifiers to correct errors in a discrete stepped gain control. A digital gain control circuit controls both the digital amplifier and at least one analog amplifier to produce a smooth linear and continuous gain, wherein perturbations in the digital control of gain are smoothed by a signal applied to gain control circuit by a gain step correction circuit.

US Patent:

20130216009, Aug 22, 2013

Filed:

Mar 18, 2013

Appl. No.:

13/845377

Inventors:

James Qiu - Carlsbad CA, US
Sridhar Ramesh - Carlsbad CA, US
Sheng Ye - Carlsbad CA, US
Curtis Ling - Carlsbad CA, US

International Classification:

H03G 3/20

US Classification:

375344, 375345

Abstract:

A communication receiver which applies signal processing for quantitatively estimating receive signal factors such as communication channel quality, signal characteristics, and overall system received bit error rate (BER)or packet error rate (PER) and which applies a general algorithm for mapping these estimated factors to control receiver performance and minimize power consumption.

US Patent:

20170041062, Feb 9, 2017

Filed:

Oct 18, 2016

Appl. No.:

15/296544

Inventors:

- San Diego CA, US
Ian Riphagen - San Diego CA, US
James Xiaohui Qiu - San Diego CA, US
In Kwang Kim - San Diego CA, US

International Classification:

H04B 7/155
H04W 52/52

Abstract:

An antenna system includes a donor antenna sub-system, a server antenna sub-system, and a processor to optimize the gain of the repeater in the system. The gain in the antenna system is increased by optimizing the isolation between the donor and/or server antenna sub-systems according to a cost function.