Kohei T Fujii

US Patent:

7400200, Jul 15, 2008

Filed:

Mar 17, 2006

Appl. No.:

11/378986

Inventors:

Kohei Fujii - San Jose CA, US
Michael L. Frank - Los Gatos CA, US

Assignee:

Avago Technologies Wireless IP Pte Ltd - Singapore

International Classification:

H03F 3/68

US Classification:

330295, 330296

Abstract:

An integrated circuit including a distributed amplifier is disclosed. The integrated circuit includes a plurality of amplification stages, each stage connected to an input signal and an output signal. At least one amplification stage includes an amplification transistor such as a field effect transistor (FET) having a gate, a source, and a drain, the gate connected to the input signal and a feedback path between the drain and the gate. The feedback path is implemented with another FET having a gate, a source, and a drain; its gate is connected to a control signal; its drain is connected to the drain of the amplification FET; and its source is connected to the gate of the amplification FET. The feedback path provides variable resistive feedback and allows the amplification FET to operate at its linear response portion of its characteristic curve even when its gain is controlled by a control signal.

US Patent:

7474156, Jan 6, 2009

Filed:

May 25, 2007

Appl. No.:

11/753706

Inventors:

Kohei Fujii - San Jose CA, US

Assignee:

Avago Technologies Wireless IP (Singapore) Pte. Ltd. - Singapore

International Classification:

H03F 3/68

US Classification:

330295, 330124 R, 330 53

Abstract:

An amplifier has an input port, an output port, N gain elements in parallel, an input power splitter coupled between the input port of the amplifier and the input ports of the N gain elements, an output resistor chain extending between the output ports of the first through Nth gain elements, and an output power combiner coupled between the output ports of the N gain elements and the output port of the amplifier. The output power combiner presents a corresponding input impedance to each of the N gain elements. At least two of the input impedances presented by the output power combiner to the N gain elements are substantially different from each other.

US Patent:

7509112, Mar 24, 2009

Filed:

Nov 16, 2004

Appl. No.:

10/990647

Inventors:

Kohei Fujii - San Jose CA, US

Assignee:

Avago Technologies Wireless IP (Singapore) Pte. Ltd. - Singapore

International Classification:

H04B 1/26

US Classification:

455327, 455333, 455323, 455324, 455325, 327 76, 327113, 327333, 327356, 327359

Abstract:

An image rejection mixer including a first and a second hybrid couplers and a first and a second traveling-wave mixers is disclosed. The first hybrid coupler divides an input radio frequency (RF) signal to a first RF signal and a second RF signal, the second RF signal being in quadrature to the first RF signal. The first traveling-wave mixer mixes the first RF signal and a local oscillator (LO) signal to produces a first intermediate frequency (IF) signal. The second traveling-wave mixer mixes the second RF signal and the local oscillator signal to produces a second IF signal. The second hybrid coupler combines the first IF signal and the second IF signal to produce an upper sideband of the IF signals and a lower sideband of the IF signals. The use of the traveling-wave mixers allow for a wide bandwidth operation of the image rejection mixer.

US Patent:

7512394, Mar 31, 2009

Filed:

Nov 16, 2004

Appl. No.:

10/990842

Inventors:

Kohei Fujii - San Jose CA, US

Assignee:

Avago Technologies Wireless IP (Singapore) Pte. Ltd. - Singapore

International Classification:

H04B 1/26

US Classification:

455327, 455333, 455323, 455324, 455325, 327 76, 327113, 327333, 327356, 327359

Abstract:

An up-conversion mixer includes a first and a second hybrid couplers and a first and a second traveling-wave mixers is disclosed. The first hybrid coupler receives an input intermediate frequency (IF) signal and produces a first IF signal (IF) and a second IF (IF) signal, the second IF signal being 180 degree off-phase compared to the first IF signal. The first traveling-wave mixer mixes the first IF signal (IF) and a first local oscillator (LO) signal to produces a first radio frequency signal (RF). The second traveling-wave mixer mixes the second IF signal (IF) and a second local oscillator signal (LO) to produces a second RF signal (RF). The second hybrid coupler to combines the first RF signal and the second RF signal to produce an output RF signal. The use of the traveling-wave mixers allow for a wide bandwidth operation of the up-conversion mixer.

US Patent:

8416024, Apr 9, 2013

Filed:

Apr 19, 2011

Appl. No.:

13/089385

Inventors:

Kohei Fujii - San Jose CA, US

Assignee:

Avago Technologies Wireless IP (Singapore) Pte. Ltd. - Singapore

International Classification:

H03F 3/191

US Classification:

330302, 330295

Abstract:

An amplifier having an operating frequency includes: an input port and an output port; three gain elements, each having an input terminal and an output terminal; an input matching network; and an output matching network. The input matching network includes: a first microstrip line which is connected to the input port and is an inductor at the operating frequency; a second microstrip line extending between the input terminals of the three gain elements; and a first split shunt capacitor connecting the first microstrip line to the second microstrip line. The output matching network includes: a third microstrip line which is connected to the output port and is an inductor at the operating frequency; a fourth microstrip line extending between the output terminals of the three gain elements; and a second split shunt capacitor connecting the third microstrip line to the fourth microstrip line.

US Patent:

20070001765, Jan 4, 2007

Filed:

Jul 2, 2005

Appl. No.:

11/173378

Inventors:

Kohei Fujii - San Jose CA, US

International Classification:

H03F 3/26

US Classification:

330276000

Abstract:

Monolithic transformer based amplifier for integrated circuits. The amplifier includes an input transformer with a first impedance transforming ratio. The input transformer includes a coupled line structure. An amplification circuit is coupled to the input transformer. The amplifier also includes an output transformer with a second impedance transforming ratio that is coupled to the amplification circuit.

US Patent:

20220321062, Oct 6, 2022

Filed:

Mar 31, 2021

Appl. No.:

17/219118

Inventors:

- Lowell MA, US
Shamit Som - Chelmsford MA, US
Kohei Fujii - San Jose CA, US
Quinn Martin - Lowell MA, US
Walter Nagy - Lowell MA, US

International Classification:

H03F 1/22
H03F 3/195

Abstract:

Various aspects of integrated amplifiers, layouts for the integrated amplifiers, and packaged arrangements of the amplifiers are described. In one example, an amplifier includes an amplifier cell, and a biasing network coupled to the common gate transistor in the amplifier cell. The amplifier cell includes a common source transistor and a common gate transistor in a cascode arrangement, where at least one of the common source transistor and the common gate transistor comprises a field plate. Among other advantages, the amplifiers described herein can be biased with relatively high voltages and still operate like a single a common source transistor, without sacrificing reliability, performance, or requiring additional off-chip components, such as biasing networks of resistors and inductors.

US Patent:

20200105686, Apr 2, 2020

Filed:

Sep 28, 2018

Appl. No.:

16/146302

Inventors:

- Lowell MA, US
Kohei Fujii - San Jose CA, US

International Classification:

H01L 23/66
H03F 3/195
H01L 23/00
H01L 23/043

Abstract:

Examples of a package for a flange mount device are described. In one example, the package includes a thermally conductive base, a base substrate, and a lid having a cavity. The base substrate includes a through hole and radio frequency (RF) input, RF output, and bias traces that extend to a perimeter of the through hole. The lid includes a cavity and RF input coupling, RF output coupling, and bias coupling traces. A device can be secured to the thermally conductive base, and the lid can be secured to the thermally conductive base, with the base substrate secured between the lid and the thermally conductive base, coupling the traces of the base substrate to the traces of the lid. Other components, such as biasing, blocking, and bypassing components can be easily integrated into the package. Impedance matching and electromagnetic shielding components can also be easily integrated into the package.