Chi L Wang

US Patent:

6600394, Jul 29, 2003

Filed:

Jun 6, 2000

Appl. No.:

09/587805

Inventors:

Chi Wang - Middletown NJ
Gregory J. Lamont - Jackson NJ
William D. Blair - Lanoka Harbor NJ
William H. Holland - Pennington NJ

Assignee:

Radio Frequency Systems, Inc. - Meriden CT

International Classification:

H01P 700

US Classification:

333235, 333231

Abstract:

A tunable, temperature compensated, thermal and mechanical stable, dielectric loaded cavity resonator and filter assembly has high unloaded Q, wide frequency tuning range and simple structure suitable for high volume production. The cavity resonator consists of a conductive housing, a substantially cylindrical ring shape dielectric body with a low loss, low thermal expansion coefficient support, a tuning mechanism and a plastic support at the opposite side of the main cylindrical dielectric body, which holds the main cylindrical dielectric body in place. The tuning mechanism further includes a substantially cylindrical dielectric tuning element positioned in or near the hole of the main cylindrical dielectric body and a self-locked or equivalent nut locked rotor with a support using the same material as that of the main cylindrical body support. The rotor is accessible and rotational movable from the outside of the conductive enclosure, resulting in linear motion of the dielectric tuning element with respect to the main dielectric body. Therefore the resonant frequency of the resonator can be substantially adjusted.

US Patent:

6624722, Sep 23, 2003

Filed:

Sep 12, 2001

Appl. No.:

09/949660

Inventors:

Chi Wang - Middletown NJ
William D. Wilber - Neptune NJ

Assignee:

Radio Frequency Systems, Inc. - Meriden CT

International Classification:

H01P 518

US Classification:

333116, 333117, 333111

Abstract:

A microwave coupler has a planar form with a transmission line segment oriented at an angle relative to a main transmission line. The planar form of the transmission line, such as in a printed circuit board, helps reduce the size and manufacturing costs for the coupler. When placed a prescribed distance from the main transmission line and oriented at an appropriate angle, the directivity and coupling factor requirements can be met precisely with minimal tuning. Where fine tuning is required, a tuning screw and resistor disposed adjacent to the transmission line segment are provided.

US Patent:

6624723, Sep 23, 2003

Filed:

Jul 10, 2001

Appl. No.:

09/901059

Inventors:

Chi Wang - Middletown NJ

Assignee:

Radio Frequency Systems, Inc. - Meriden CT

International Classification:

H01P 1213

US Classification:

333134, 333203, 333230

Abstract:

A multi-channel multiplexer has a substantially square shape and includes an NÃN matrix with a common resonator. A plurality of input/output ports are connected to a common input/output port via respective resonators of the NÃN matrix and the common resonator. The multiplexer provides a compact size, with balanced insertion losses and simple configuration to minimize phase difference of inter-resonator transitions.

US Patent:

6806791, Oct 19, 2004

Filed:

Feb 29, 2000

Appl. No.:

09/514879

Inventors:

Chi Wang - Middletown NJ
William Deppen Blair - Lanoka Harbor NJ

Assignee:

Radio Frequency Systems, Inc. - Marlboro NJ

International Classification:

H01P 120

US Classification:

333134, 333202, 333206, 333230

Abstract:

The invention is related to the field of tunable multiplexers. It consists of a tunable microwave multiplexer comprising a plurality of channel filters coupled to a combining/dividing mechanism. The plurality of channel filters can be either dielectric loaded resonators or combline resonators, while the combining/dividing mechanism can be a common resonator. In one embodiment, the common resonator is a multiple half-wavelength coaxial resonator.

US Patent:

6853271, Feb 8, 2005

Filed:

Nov 14, 2001

Appl. No.:

09/987353

Inventors:

William D. Wilber - Neptune NJ, US
Chi Wang - Holmdel NJ, US
Weili Wang - Oldbridge NJ, US

Assignee:

Radio Frequency Systems, Inc. - Meriden CT

International Classification:

H01P001/20
H01P007/00

US Classification:

333209, 333202, 333219

Abstract:

The present invention incorporates triple-mode, mono-block resonators that are smaller and less costly. The size reduction has two sources. First, the triple-mode mono-block resonator has three resonators in one block. This provides a 3-fold reduction in size compared to filters currently used which disclose one resonator per block. Secondly, the resonators are not air-filled coaxial resonators as in the standard combline construction, but are dielectric-filled blocks. The coupling between modes is accomplished by the corner cuts. One oriented along the Y axis and one oriented along the Z axis. In addition, a third corner cut along the X axis can be used. Corner cuts are used to couple a mode oriented in one direction to a mode oriented in a second mutually orthogonal direction. Each coupling represents one pole in the filter's response. Therefore, the triple-mode mono-block discussed above represents the equivalent of three poles or three electrical resonators.

US Patent:

7042314, May 9, 2006

Filed:

Oct 23, 2002

Appl. No.:

10/277971

Inventors:

Chi Wang - Holmdel NJ, US
Weili Wang - Old Bridge NJ, US
William D. Wilber - Jackson NJ, US
William D. Blair - Freehold NJ, US

Assignee:

Radio Frequency Systems - Meriden CT

International Classification:

H01P 1/20
H01P 1/208
H01P 7/10

US Classification:

333202, 3332191, 333209

Abstract:

A delay filter uses the dielectric mono-block triple-mode resonator and unique inter-resonator coupling structure, having smaller volume and higher power handling capacity. The triple-mode mono-block resonator has three resonators in one block. An input/output probe is connected to each metal plated dielectric block to transmit microwave signals. Corner cuts couple a mode oriented in one direction to a mode oriented in a second, mutually orthogonal direction. An aperture between two blocks couples all six resonant modes, and generates two inductive couplings by magnetic fields between two modes, and one capacitive coupling by electric fields. The input/output probes, coupling corner cuts and aperture are aligned such that all six resonators are coupled in the desired value and sign, so constant delay on the transmitted signal within certain bandwidth can be achieved. By connecting the input and output probes to the base printed circuit board, the delay filter is surface mountable.

US Patent:

7068127, Jun 27, 2006

Filed:

Nov 14, 2001

Appl. No.:

09/987376

Inventors:

William D. Wilber - Neptune NJ, US
Chi Wang - Holmdel NJ, US
Weili Wang - Oldbridge NJ, US

Assignee:

Radio Frequency Systems - Meriden CT

International Classification:

H01P 1/20
H01P 7/00

US Classification:

333202, 3332191, 333235

Abstract:

The present invention incorporates triple-mode, mono-block resonators that are tunable. Four novel and unobvious methods of tuning are disclosed. The first tuning method is to mechanically grind areas on three orthogonal faces of the mono-block in order to change the resonant frequencies of the three modes in each block. Another method of tuning frequency is to cut a slot within a face of the resonator. A third method of tuning the mono-block is to tune the resonant frequency of a particular mode by removing small circular areas of the conductive surface from a particular face of the mono-block. The fourth, tuning method is the use of discrete tuning elements, with 3 elements distributed among three orthogonal faces of the mono-block, to affect the necessary change of the resonant frequencies.

US Patent:

8366449, Feb 5, 2013

Filed:

Aug 13, 2008

Appl. No.:

12/190748

Inventors:

Chi Wang - Carmel IN, US

International Classification:

G09B 3/01

US Classification:

434322, 434365, 434156, 434319, 434308, 273429

Abstract:

The present invention includes method and system for intelligent knowledge diagnosis and tutoring in any knowledge domain. It differs from prior arts with new knowledge model for knowledge presentation and heuristic algorithms. The knowledge model allows the present invention to be applied to curricula in different knowledge domains quickly and cost effectively. The knowledge model and related computational algorithms provide effective and intelligent knowledge diagnosis and tutoring with minimum requirement on assessment content and learning content. It also allows easy curriculum customization and learner initiated learning assistance to meet needs of different teaching and learning styles. The present invention gains better understanding of learner's knowledge status and hence provides more accurate assistance as learner progresses in the curriculum. The present invention can be an add-engine to existing learning management systems working with existing assessment and learning content in any format.