Hui C Wu

US Patent:

6396359, May 28, 2002

Filed:

Apr 13, 2000

Appl. No.:

09/548688

Inventors:

Seyed-Ali Hajimiri - Pasadena CA
Hui Wu - Pasadena CA

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

H03B 518

US Classification:

331 96, 331 34, 331 36 C, 331 99, 331117 D, 331177 R, 331177 V

Abstract:

Techniques and structures for tuning integrated, distributed voltage-controlled oscillators (DVCOs) across a wide microwave frequency range are disclosed. One type of DVCO implements a tuning circuit that includes a pair of interconnected amplifying transistors and a current source connected to the transistors, such that a differential voltage input to the circuit adjusts the current to each transistor and effectively adjusts the âelectrical lengthâ of one of the transmission lines on which the output frequency is oscillating. This, in turn, adjusts the time delay and thus frequency of the signal propagating on the lines across a wide frequency band. This technique is called âcurrent-steering. â In a preferred embodiment, the tuning circuit is balanced with a complementary tuning circuit to effectively adjust the electrical length of the second transmission line in the oscillator. In another technique that provides for more coarse, but wider range, broadband frequency tuning, the time delay, and thus, frequency, of the DVCO is adjustable by varying the capacitive loading on the transmission lines, by introducing a coupling capacitor between the transmission lines and tuning the intrinsic capacitances of the gain transistors with a dc bias input.

US Patent:

6529085, Mar 4, 2003

Filed:

Feb 14, 2002

Appl. No.:

10/076945

Inventors:

Seyed-Ali Hajimiri - Pasadena CA
Hui Wu - Pasadena CA

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

H03B 518

US Classification:

331 96, 331 34, 331 36 C, 331117 D, 331177 R, 331177 V

Abstract:

Techniques and structures for tuning integrated, distributed voltage-controlled oscillators (DVCOs) across a wide microwave frequency range are disclosed. One type of DVCO implements a tuning circuit that includes a pair of interconnected amplifying transistors and a current source connected to the transistors, such that a differential voltage input to the circuit adjusts the current to each transistor and effectively adjusts the âelectrical lengthâ of one of the transmission lines on which the output frequency is oscillating. This, in turn, adjusts the time delay and thus frequency of the signal propagating on the lines across a wide frequency band. This technique is called âcurrent-steering. â In a preferred embodiment, the tuning circuit is balanced with a complementary tuning circuit to effectively adjust the electrical length of the second transmission line in the oscillator. In another technique that provides for more coarse, but wider range, broadband frequency tuning, the time delay, and thus, frequency, of the DVCO is adjustable by varying the capacitive loading on the transmission lines, by introducing a coupling capacitor between the transmission lines and tuning the intrinsic capacitances of the gain transistors with a dc bias input.

US Patent:

6853260, Feb 8, 2005

Filed:

Sep 19, 2002

Appl. No.:

10/246998

Inventors:

Seyed-Ali Hajimiri - Pasadena CA, US
Hui Wu - Pasadena CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

H03B005/18

US Classification:

331 96, 331107 SL, 331107 DP, 331 99

Abstract:

A voltage controlled oscillator is provided. The voltage controlled oscillator includes a differential transmission line and another transmission line, which can include a second differential transmission line or other suitable transmission lines. An active device connected to the differential transmission line and the other transmission line controls the current flow between the two transmission lines. A tuning circuit connected to the active device, such as a bias voltage, controls an oscillation frequency of a signal on the differential transmission line and the other transmission line, such as by controlling the level of current flow.

US Patent:

6867656, Mar 15, 2005

Filed:

Jun 17, 2003

Appl. No.:

10/463264

Inventors:

Seyed-Ali Hajimiri - Pasadena CA, US
Hui Wu - Pasadena CA, US

Assignee:

California Institute of Technology - Pasadena CA

International Classification:

H03B005/12
H03B019/06
H03B027/00

US Classification:

331 45, 331 75, 331117 FE, 331172, 331177 V, 327118, 327254

Abstract:

A system for generating in-phase and quadrature phase signals is provided. The system includes a first and a second differential output, such as from a sinusoidal oscillator. A first injection-locked frequency divider, such as one that uses an LC oscillator in conjunction with cross-coupled transistors, receives the first differential output and generates a in-phase or in-phase output. A second injection-locked frequency divider receives the second differential output and generates a quadrature phase output.

US Patent:

7256573, Aug 14, 2007

Filed:

Mar 31, 2005

Appl. No.:

11/095231

Inventors:

Rahul Magoon - Irvine CA, US
Scott Kee - Pasadena CA, US
Ichiro Aoki - Arcadia CA, US
Frank Carr - Newport Coast CA, US
Hui Wu - Pasadena CA, US
Jerry Twomey - Escondido CA, US
Seyed-Ali Hajimiri - Pasadena CA, US

Assignee:

Axiom Microdevices, Inc. - Irvine CA

International Classification:

G01R 27/02

US Classification:

324 95, 324117 R, 324127

Abstract:

A distributed active transformer on a semiconducting substrate is provided. The distributed active transformer includes an outer primary, a secondary disposed adjacent to the outer primary, and an inner primary disposed adjacent to the outer primary and the secondary. A plurality of first three terminal devices is coupled to the outer primary at a plurality of locations. A plurality of second three terminal devices coupled to the inner primary at a plurality of locations, and each second three terminal device is disposed opposite from and coupled to one of the plurality of first three terminal devices. A plurality of power control actuation circuits is also provided, where each power control actuation circuit is coupled to one of the first three terminal devices and the second three terminal devices.

US Patent:

7471153, Dec 30, 2008

Filed:

Oct 28, 2004

Appl. No.:

10/975316

Inventors:

Scott D. Kee - Lynnwood CA, US
Ichiro Aoki - Arcadia CA, US
Hui Wu - Pasadena CA, US
Seyed-Ali Hajimiri - Pasadena CA, US
Frank Carr - Newport Coast CA, US
Rabul Magoon - Irvine CA, US
Alexandre Kral - Laguna Niguel CA, US
Afshin Mellati - Laguna Niguel CA, US
Florian Bohn - Goleta CA, US
Donald McClymont - Dana Point CA, US

Assignee:

Axiom Microdevices, Inc. - Irvine CA

International Classification:

H03F 3/68

US Classification:

330295, 330307, 330276, 333100

Abstract:

An integrated power combiner is disclosed. The power combiner includes a first circular geometry primary winding having one or more inductive elements, such as an active winding with one or more driver stages. A circular geometry secondary winding is disposed adjacent to the first primary winding, such as an active winding with one or more driver stages. A second circular geometry primary winding is disposed adjacent to the secondary winding and has one or more inductive elements. One or more connections are provided between one or more of the inductive elements of the first circular geometry primary winding and one or more of the inductive elements of the second circular geometry primary winding.

US Patent:

20040222859, Nov 11, 2004

Filed:

May 8, 2003

Appl. No.:

10/434297

Inventors:

Seyed-Ali Hajimiri - Pasadena CA, US
Hui Wu - Pasadena CA, US

International Classification:

H03B011/10

US Classification:

331/1070DP

Abstract:

A voltage controlled oscillator is provided. The voltage controlled oscillator includes a traveling-wave amplifier having two inputs and two outputs, such as would be formed by a first transmission line having a first input and a first output and a second transmission line having a second input and a second output. The first output of the traveling-wave amplifier is connected to the first input. A delay is connected between the second output and the second input, so as to provide a voltage controlled oscillator that requires minimal power to operate.

US Patent:

20050093637, May 5, 2005

Filed:

Nov 15, 2004

Appl. No.:

10/988681

Inventors:

Seyed-Ali Hajimiri - Pasadena CA, US
Hui Wu - Pasadena CA, US

International Classification:

H03B005/18

US Classification:

3311070DP

Abstract:

A voltage controlled oscillator is provided. The voltage controlled oscillator includes a traveling-wave amplifier having two inputs and two outputs, such as would be formed by a first transmission line having a first input and a first output and a second transmission line having a second input and a second output. The first output of the traveling-wave amplifier is connected to the first input. A delay is connected between the second output and the second input, so as to provide a voltage controlled oscillator that requires minimal power to operate.