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John F Sevic

from Los Gatos, CA
Age ~55

John Sevic Phones & Addresses

  • 243 Long Ridge Rd, Los Gatos, CA 95032 (408) 356-8889
  • 129 Wheeler Ave, Los Gatos, CA 95030 (408) 358-3501
  • Santa Clara, CA
  • San Francisco, CA
  • San Diego, CA
  • Syracuse, NY
  • Phoenix, AZ
  • Carlsbad, CA
  • Sunnyvale, CA
  • Buffalo Grove, IL

Publications

Us Patents

Waveform Pershaping For Efficiency Improvements In Dc To Rf Conversion

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US Patent:
6624695, Sep 23, 2003
Filed:
Oct 31, 2001
Appl. No.:
09/999090
Inventors:
John Sevic - Los Gatos CA
Khan M. Salam - Livermore CA
Assignee:
Tropian, Inc. - Cupertino CA
International Classification:
H03F 126
US Classification:
330149, 330126
Abstract:
High efficiency DC to RF conversion with use of active harmonic insertion is provided for power amplification over a wide dynamic range of input signal level. Specifically, a power amplifier device including at least a final amplification stage is operated to receive an input signal of a fundamental frequency. A drive signal is produced which includes a fundamental signal component of the fundamental frequency and at least one harmonic signal component of a harmonic frequency that is substantially an integer multiple of the fundamental frequency, wherein relative phase shift and relative amplitude of the components are controlled over at least an order of magnitude of dynamic range of the input signal. As the signal level of the input signal decreases (or increases), the desired proportion of signal levels is maintained between the components. The drive signal is provided to the power amplifier device, and in response to the drive signal, an amplified output signal is produced at the final amplification stage.

Differential Rf/Microwave Power Amplifier Using Independent Synchronized Polar Modulators

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US Patent:
6653896, Nov 25, 2003
Filed:
Nov 30, 2001
Appl. No.:
09/997743
Inventors:
John F. Sevic - Los Gatos CA
Wendell B. Sander - Los Gatos CA
Stephan V. Schell - San Francisco CA
Assignee:
Tropian, Inc. - Cupertino CA
International Classification:
H03F 338
US Classification:
330 10, 330124 R, 332102
Abstract:
A first amplified signal is produced at a first amplifier, a second amplified signal is produced at a second amplifier, and a differential signal representing difference between the first amplified signal and the second amplified signal is generated at a subtraction unit receiving the first amplified signal and second amplified signal, the differential signal being a final amplified signal having a final modulated amplitude and a final modulated phase.

Current Source Bias Circuit With Hot Carrier Injection Tracking

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US Patent:
6720228, Apr 13, 2004
Filed:
Oct 18, 2000
Appl. No.:
09/691949
Inventors:
John F. Sevic - Los Gatos CA
Francois Hebert - San Mateo CA
Assignee:
Cree Microwave, Inc. - Sunnyvale CA
International Classification:
H01L 21336
US Classification:
438307, 438383, 438286
Abstract:
A current mirror bias circuit for an RF amplifier transistor is modified whereby the reference transistor of the current mirror tracks hot carrier degradation in the RF transistor. Gate bias to the current mirror transistor is modified whereby the drain-to-gate voltage can be positive, and the lightly doped drain region in the lateral n-channel reference transistor is shortened and dopant concentration increased to increase the electric field of the reference transistor to provide the hot carrier injection degradation characteristics similar to the main transistor. Additionally, the gate length of the reference transistor can be shortened to effect the hot carrier injection degradation.

Method And Apparatus For Model Extraction

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US Patent:
2006011, Jun 1, 2006
Filed:
Nov 30, 2004
Appl. No.:
11/001692
Inventors:
John Sevic - Los Gatos CA,
Gary Simpson - Fontana CA,
International Classification:
G06F 17/50
US Classification:
703013000
Abstract:
A method and apparatus for extracting a model of a device under test (DUT), wherein an extraction-space protocol is defined, a set of measurement data on the DUT is extracted in accordance with the extraction-space protocol, and a DUT model extracted from the set of measurement data collected over the extraction-space, corresponding to a combination of parameters within the extraction-space.

Rf Power Transistor Having Cascaded Cells With Phase Matching Between Cells

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US Patent:
6297700, Oct 2, 2001
Filed:
Feb 18, 2000
Appl. No.:
9/507123
Inventors:
John F. Sevic - Los Gatos CA
Christopher J. Knorr - Los Gatos CA
James R. Parker - Cupertino CA
Howard D. Bartlow - Palo Alto CA
Assignee:
UltraRF, Inc. - Sunnyvale CA
International Classification:
H01L 2348
H01L 2710
H01L 2976
US Classification:
330277
Abstract:
The power delivered by an RF power transistor having cascaded cells or unit elements is improved by reducing the phase imbalance between elements and thereby reducing transverse effects between cells. Phase imbalance is reduced by varying the number of transistor elements connected to interconnect areas, connecting wire bonds to an input transmission line concentrated near an outer edge in the transmission line to take advantage of surface skin effects on current, and varying the surface area of the interconnect areas to adjust input impedance and output impedance of each cell.

Current Source Bias Circuit With Hot Carrier Injection Tracking

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US Patent:
6201444, Mar 13, 2001
Filed:
Sep 1, 1999
Appl. No.:
9/388295
Inventors:
John F. Sevic - Los Gatos CA
Francois Hebert - San Mateo CA
Assignee:
Spectrian Corporation - Sunnyvale CA
International Classification:
H03F 304
US Classification:
330288
Abstract:
A current mirror bias circuit for an RF amplifier transistor is modified whereby the reference transistor of the current mirror tracks hot carrier degradation in the RF transistor. Gate bias to the current mirror transistor is modified whereby the drain-to-gate voltage can be positive, and the lightly doped drain region in the lateral n-channel reference transistor is shortened and dopant concentration increased to increase the electric field of the reference transistor to provide the hot carrier injection degradation characteristics similar to the main transistor. Additionally, the gate length of the reference transistor can be shortened to effect the hot carrier injection degradation.

Efficient Parallel-Stage Power Amplifier

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US Patent:
5872481, Feb 16, 1999
Filed:
Dec 9, 1996
Appl. No.:
8/767124
Inventors:
John F. Sevic - San Diego CA
Richard J. Camarillo - San Diego CA
Assignee:
QUALCOMM Incorporated - San Diego CA
International Classification:
H03F 368
US Classification:
330 51
Abstract:
An amplifier circuit for providing an amplified signal in response to an input signal. The amplifier circuit includes an input network for applying the input signal to a selected at least one of a plurality of amplifier stages. An output network is provided for coupling the amplified signal from the selected at least one amplifier stage. The appropriate amplifier stage is selected by a control circuit in response to a desired power value of the amplified signal. By selectively activating only the amplifier stage(s) that are necessary to provide the desired level of output power, increased DC efficiency can be accomplished in applications that require an amplifier which operates linearly over a wide dynamic range.

Dual-Mode Amplifier With High Efficiency And High Linearity

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US Patent:
6137355, Oct 24, 2000
Filed:
Oct 28, 1999
Appl. No.:
9/430670
Inventors:
John F. Sevic - San Diego CA
Richard J. Camarillo - San Diego CA
International Classification:
H03F 368
US Classification:
330 51
Abstract:
An amplifier circuit having a high linearity mode of operation and a high efficiency mode of operation. The amplifier circuit comprises an amplifier having a variable active device periphery and a variable supply voltage; and a control circuit, coupled to the amplifier, for decreasing the variable active device periphery and increasing the variable supply voltage when in the high linearity mode of operation, and for increasing the variable active device periphery and decreasing the variable supply voltage when in the high efficiency mode of operation.
John F Sevic from Los Gatos, CA, age ~55 Get Report