Lawrence K Larson

US Patent:

6396347, May 28, 2002

Filed:

May 3, 2001

Appl. No.:

09/848855

Inventors:

Donald Y. Lie - San Diego CA
Lawrence E. Larson - Del Mar CA

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H03G 310

US Classification:

330285, 330133

Abstract:

In a low-heightened power, low-heightened noise dual gain amplifier, first and second, transistors have their emitter-collector circuits connected in series between the ground and a bus voltage. A radio frequency input terminal is coupled to the bases of both transistors. The first transistor is connected across the ground and an output terminal and operated in the common emitter mode. The first transistor operates as a high gain amplifier. A second transistor is connected across the output terminal and a bus voltage. First and second switching transistors switch first and second biasing sources to render first and second amplifier transistors conducted for operation in the high gain or low gain mode. Additionally, a third switching transistor is ac coupled across the input terminals of the first and second amplifier transistors. The third switching transistor is biased along with the first switching transistor for selectively coupling the RF input to the high gain or low gain amplifying transistor.

US Patent:

6504447, Jan 7, 2003

Filed:

Oct 30, 1999

Appl. No.:

09/431308

Inventors:

David Laney - San Diego CA
Mehran Matloubian - Encino CA
Lawrence Larson - Del Mar CA

Assignee:

HRL Laboratories, LLC - Malibu CA

International Classification:

H03G 1104

US Classification:

333 172, 333262, 200181

Abstract:

The present invention provides a flexible mechanical bridge over a microstrip on a substrate, which utilizes an electromagnetic field increase, as generated by temporary power surge to shunt harmful power away from a MMIC system. The invention includes a power limiter which includes an airbridge , preferably in the form of an electrically conductive strip with ground contacts and formed thereon. The ground contacts and are electrically connected, through via holes and respectively, to a metallization layer formed on the bottom side of a substrate. The air bridge is designed such that it traverses an electrically conductive microstrip forming an air gap between the air bridge and the electrically conductive microstrip. When there is a power surge the air bridge , will flex to cause an electrical connection with the microstrip , thereby directing the unwanted signal through the ground contacts and and the via holes and to the metallization layer.

US Patent:

6735424, May 11, 2004

Filed:

Jun 14, 2000

Appl. No.:

09/595508

Inventors:

Lawrence Larson - San Diego CA
Wei Xiong - San Diego CA

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H04B 106

US Classification:

4552501, 455126, 455127, 330285, 330136

Abstract:

A discrete low-noise amplifier designed to operate in a mobile wireless environment uses two cascaded GaAs FETs to achieve 25 dB gain and 0. 9 dB noise figure at 2. 5 GHz. Active bias control circuitry responsive to monitored amplifier output power automatically and continuously adjusts the drain-source currents, and the load lines, of the cascaded FETs to (i) maintain power consumption at 33 milliwatts in nominal small-signal conditions, and to (ii) provide an elevated input third-order intermodulation intercept point (IP3) and a reduced noise figure during the presence of jamming. A 15 dB improvement in the input IP3 is achieved in large-signal operation. Amplifier operation is supported by an a. c. power detector of enhanced sensitivity and responsiveness because of un-grounded operation.

US Patent:

6847266, Jan 25, 2005

Filed:

Jan 6, 2003

Appl. No.:

10/337967

Inventors:

David Laney - La Jolla CA, US
Mehran Matloubian - Encino CA, US
Lawrence Larson - Del Mar CA, US

Assignee:

HRL Laboratories, LLC - Malibu CA

International Classification:

H01P 124

US Classification:

333 12, 333262

Abstract:

Microelectromechanical RF and microwave frequency power limiter and electrostatic protection devices for use in high-speed circuits are presented. The devices utilize an airbridge or a cantilever arm including a contact pad positioned operatively adjacent to an electrically conductive and substantially planar transmission line. When the power level in the transmission line exceeds a particular threshold, the airbridge or cantilever arm yields due to force between the contact pad and the transmission line, directing undesired power away from active devices. This characteristic can either serve as a method by which to limit the amount of power passing through the transmission line to a determined value or as a method by which to protect devices along the transmission line from damage due to large electrostatic bursts.

US Patent:

6915117, Jul 5, 2005

Filed:

May 3, 2001

Appl. No.:

09/850629

Inventors:

Paul P. Chominski - San Diego CA, US
Jonathan L. Kennedy - Auburn CA, US
Lawrence E. Larson - Del Mar CA, US
Joshua C. Park - Medford MA, US

Assignee:

International Business Machines Corporation - Armonk NY

International Classification:

H04B001/26

US Classification:

455118, 455112, 455113, 455260, 455 20

Abstract:

In a multiple stage transmitter, and analog signal is modulated and mixed to produce a radio frequency output. A separate mixing frequency signal is provided to each stage. A single frequency synthesizer is used rather than a plurality of frequency synthesizers. In a two-stage system, first and second dividers each receive the output of the frequency synthesizer and deliver a mixing signal to the first and second stages respectively. The modulus of each divider may be selected to minimize spurious signals.

US Patent:

7652532, Jan 26, 2010

Filed:

Sep 5, 2006

Appl. No.:

11/515584

Inventors:

Mingyuan Li - La Jolla CA, US
Peter Asbeck - Del Mar CA, US
Ian Galton - Del Mar CA, US
Lawrence E. Larson - Del Mar CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H03F 1/32

US Classification:

330149, 4551152

Abstract:

The invention provides methods and devices for estimating power amplifier nonlinearity using simple correlation techniques. Methods and devices of the invention can monitor a power amplifier that has digitally modulated inputs and an output containing more than one signal stream. A preferred method of the invention creates a test signal by forming the products of several pseudorandom noise sequences from the digitally modulated inputs to the power amplifier. Nonlinear contributions of the power amplifier output are determined by cross-correlating the test signal and the total output signal of the power amplifier. In preferred embodiments, the determined nonlinear contributions of the power amplifier are used to introduce corrective predistortion in the power amplifier.

US Patent:

RE41582, Aug 24, 2010

Filed:

May 11, 2006

Appl. No.:

11/432792

Inventors:

Lawrence Larson - Del Mar CA, US
Wei Xiong - Menlo Park CA, US

Assignee:

The Regents of the University of California - Oakland CA

International Classification:

H04B 1/06

US Classification:

4552501, 4551271, 330136

Abstract:

A discrete low-noise amplifier designed to operate in a mobile wireless environment uses two cascaded GaAs FETs to achieve 25 dB gain and 0. 9 dB noise figure at 2. 5 GHz. Active bias control circuitry responsive to monitored amplifier output power automatically and continuously adjusts the drain-source currents, and the load lines, of the cascaded FETs to (i) maintain power consumption at 33 milliwatts in nominal small-signal conditions, and to (ii) provide an elevated input third-order intermodulation intercept point (IP3) and a reduced noise figure during the presence of jamming. A 15 dB improvement in the input IP3 is achieved in large-signal operation. Amplifier operation is supported by an a. c. power detector of enhanced sensitivity and responsiveness because of un-grounded operation.

US Patent:

7902585, Mar 8, 2011

Filed:

Jun 6, 2006

Appl. No.:

11/920935

Inventors:

Lawrence E. Larson - Del Mar CA, US
Leonardus C. N. de Vreede - Pijnacker, NL

Assignee:

Technical University Delft - Delft
The Regents of the University of California - Oakland CA

International Classification:

H01L 29/94

US Classification:

257312, 333174, 333176, 455302, 361278, 343745, 343702, 438379

Abstract:

An integrated variable voltage diode capacitor topology applied to a circuit providing a variable voltage load for controlling variable capacitance. The topology includes a first pair of anti-series varactor diodes, wherein the diode power-law exponent n for the first pair of anti-series varactor diodes in the circuit is equal or greater than 0. 5, and the first pair of anti-series varactor diodes have an unequal size ratio that is set to control third-order distortion. The topology also includes a center tap between the first pair anti-series varactor diodes for application of the variable voltage load. In preferred embodiments, a second pair of anti-series varactor diodes is arranged anti-parallel to the first pair of anti-series varactor diodes so the combination of the first pair of anti-series varactor diodes and the second pair of anti-series varactor diodes control second-order distortion as well.