Hui Wu 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:

6567203, May 20, 2003

Filed:

Feb 23, 2001

Appl. No.:

09/792220

Inventors:

Marc E. Hill - Woodside CA
Jonathan P. King - San Jose CA
Hui Wu - Milpitas CA

Assignee:

Big Bear Networks, Inc. - Milpitas CA

International Classification:

G02F 103

US Classification:

359254, 359237, 359245

Abstract:

The invention discloses phase-shifters, modulators, and method that produces a smaller by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear so electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

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:

6548893, Apr 15, 2003

Filed:

Jul 3, 2001

Appl. No.:

09/898567

Inventors:

Yu Ju Chen - San Ramon CA
Hui Wu - Milpitas CA

Assignee:

BigBear Networks, Inc. - Milpitas CA

International Classification:

H01L 2312

US Classification:

257704, 257693, 257710, 257728

Abstract:

An apparatus and method for hermetically sealing, EMI shielding integrated circuits for high-speed electronic devices using a combination of microstrip to buried stripline interface for signal transmission from the integrated circuit. The packaging provided comprises a first plurality of microstrips interconnecting the integrated circuit to a plurality of buried striplines exposed on a surface of the main substrate. A ceramic interposer placed over the main substrate âburiesâ a portion of the exposed striplines on the main substrate to thereby insulate these signal paths from a hermetically sealing, and EMI shielding metal lid placed over the integrated circuit. The metal lid and the seal ring brazed over the ceramic interposer thus provide both a hermetic seal and an electric radiation block. A reduction in dispersion due to the buried striplines is also achieved, as well as improving jitter performance.

US Patent:

6697260, Feb 24, 2004

Filed:

Oct 29, 2001

Appl. No.:

10/040421

Inventors:

Yu Ju Chen - San Ramon CA
Thomas J. Sleboda - Milpitas CA
Michael Zhong Xuan Wong - Milpitas CA
Hui Wu - Milpitas CA

Assignee:

Big Bear Networks, Inc. - Milpitas CA

International Classification:

H05K 500

US Classification:

361752, 361753, 361736, 361735, 361785, 361803, 361796

Abstract:

An integrated high-speed package comprising a package housing having a housing lip and connector having a center pin abutting along a bottom surface of the housing lip. For signal registration of a first substrate to the signal lead, the substrate is âfloatedâ up to the housing lip, which provides an alignment reference to ensure that the top surface of the first substrate is aligned and in direct registration with the signal lead. In another embodiment, the center pin to substrate registration is provided at a top surface of a housing base. The housing base preferably comprises a first portion of a first height and a second portion of a second height. Accordingly, the housing base can accommodate substrates of different thickness while allowing a top surface of the first and a second substrate to be coplanar to facilitate signal registration there between.

US Patent:

6738174, May 18, 2004

Filed:

Feb 23, 2001

Appl. No.:

09/792222

Inventors:

Marc E. Hill - Woodside CA
Jonathan P. King - San Jose CA
Hui Wu - Milpitas CA

Assignee:

Big Bear Networks, Inc. - Milpitas CA

International Classification:

G02F 103

US Classification:

359245, 359248, 359251, 359254, 359237, 359279, 385 2, 385 3, 385 14, 385 40, 385131, 257431

Abstract:

The invention discloses phase-shifters, modulators, and method that produces a smaller by means of a field excitation using multiple electrodes. A negative signal is introduced that travels with the positive signal, which enhances the electric field significantly. The field enhancement is provided by the superposition of the fields accumulated from each electrode. A base or substrate material can be made from any compound having linear electro-optic properties, such as lithium niobate, lithium tantalite, potassium lithium niobate, potassium titanyl phosphate or gallium-arsenide. For lithium niobate, there are two possible orientations of electric field, z-cut orientation or x-cut orientation.

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.