Alan G Cha, 832214 Lenore Dr, Glendale, CA 91206

6424299, Jul 23, 2002

Aug 9, 2001

09/925773

Alan Cha - Glendale CA
Arun Bhattacharyya - El Segundo CA

The Boeing Company - Chicago IL

H01Q 138

343700MS, 343846

A dual-band patch antenna element ( ) for circular or linear polarization. The patch element ( ) is excited by two different hybrids ( ), designed for transmit and receive bands respectively. Each hybrid ( ) electromagnetically couples a pair of orthogonal ground plane slots ( ) that excite the patch antenna ( ). The hybrid ( ) and slot ( ) dimensions for the transmit band are different from the hybrid ( ) and slot ( ) dimensions for the receive band. Isolation can be improved by connecting shunt stubs ( ) to the hybrids ( ).

6549166, Apr 15, 2003

Aug 22, 2001

09/935471

Arun Bhattacharyya - El Segundo CA
Alan Cha - Glendale CA
James McKay - Manhattan Beach CA

The Boeing Company - Seattle WA

H01Q 138

343700MS, 343846

A patch antenna is disclosed having four ports for circular polarization that suppress the TM-02 mode, resulting in a radiation pattern that is symmetric. The axial ratio performance is consequently superior to that of two-port patch antennas. A four-port patch antenna includes a patch made of an electrically conductive material, a patch substrate coupled to the patch wherein the patch substrate is made of a dielectric material, a ground plane coupled to the patch substrate wherein the ground plane is made of an electrically conductive material having at least four slots formed therein, a feed substrate coupled to the ground plane wherein the feed substrate is made of a dielectric material, and a hybrid network coupled to the feed substrate that includes a right hand circularly polarized port, a left hand circularly polarized port, and two matched terminated ports.

6751458, Jun 15, 2004

Jul 7, 2000

09/612465

Weizheng Wang - Rancho Palos Verdes CA
Donald C. D. Chang - Thousand Oaks CA
Ming U. Chang - Rancho Palos Verdes CA
Ying Feria - Manhattan Beach CA
Alan Cha - Glendale CA

The Directv Group, Inc. - El Segundo CA

H04Q 720

455427, 455447, 455443, 455 121

A communication system has a high altitude communication device generating a plurality of user link beams having a first communication characteristic and a feeder link having a first communication characteristic. A gateway terminal receives the user link beam. A user terminal receives at least one of the user link beams. The plurality of user link beams comprises a first user link beam within a first cell and a first isolation zone outside the first cell. The plurality of user link beams comprises a second user link beam having the first communication characteristic and positioned within a second cell and a second isolation zone outside said second cell. The second isolation zone overlaps the first isolation zone. The feeder link is positioned within the first isolation zone and the second isolation zone. The feeder link has the first communication characteristic.

6756937, Jun 29, 2004

Jun 6, 2000

09/588395

Donald C. D. Chang - Thousand Oaks CA
Ming U. Chang - Rancho Palos Verdes CA
Ying Feria - Manhattan Beach CA
Weizheng Wang - Rancho Palos Verdes CA
Alan Cha - Glendale CA
Kar W. Yung - Torrance CA
Frank A. Hagen - Palos Verdes Estates CA

The DIRECTV Group, Inc. - El Segundo CA

H04B 7185

342354, 455 133

A communication system including a first transceiver located on a first platform at a predetermined altitude. A first antenna is located on the first platform and connected to the first transceiver. A second antenna is connected to the other end of the first transceiver. A second transceiver is located on a ground hub physically and independent of the first platform. A third antenna is located on the ground hub and connected to the second transceiver. The third antenna is adapted to communicate with the second antenna. The first platform is maintained in a stratospheric orbit. A beamforming system is connected to the second transceiver and mounted on the ground hub. The beamforming system provides a beamformed signal from the second transceiver to the first transceiver effective to drive the first array antenna to radiate multiple beams to a surface, whereby the multiple beams create time varying and dissimilar footprints thereon. A second antenna is mounted on the first platform to receive the beamformed signal from the ground hub. The beamforming system is adapted to drive the first antenna to generate plural beams on the earths surface, each beam providing a respective footprint or cell.

6763242, Jul 13, 2004

Sep 14, 2000

09/661726

Ying Feria - Manhattan Beach CA
Ming Chang - Rancho Palos Veredes CA
Donald C. D. Chang - Thousand Oaks CA
Frank A. Hagen - Palos Verdes Estates CA
Alan Cha - Glendale CA

The DIRECTV Group, Inc. - El Segundo CA

H04B 700

455509, 455 121, 455 63, 455427, 455430, 455501

A communications system and method of operating the communications system includes a high altitude communication device that communicates with a plurality of user terminals and a gateway station. The gateway station couples the users to terrestrial networks and other users. The high altitude communication device has gateway station that assigns a first code to a beam of a first plurality of users. The gateway station continually determines whether an interference occurs between the first beam and the second beam by determining whether the first interference contour intersects the second interference contour when the first interference contour intersects the second interference contour. The gateway station declares an interference when the contours intersect and reassigns a second resource to the first beam.

6895217, May 17, 2005

Aug 21, 2000

09/644224

Donald C. D. Chang - Thousand Oaks CA, US
Alan Cha - Glendale CA, US

The DIRECTV Group, Inc. - El Segundo CA

H04B007/19

455 132, 455 121, 455427, 455429, 455430, 342354, 342372

A system has a stratospheric platform with a payload controller and a phased array antenna having a plurality of elements. A gateway station communicates with the stratospheric platform. The gateway station scales the plurality of elements to form a reconfigurable plurality of beams. The gateway station communicates a control signal to the stratospheric platform to communicate a scaling of the elements. The stratospheric platform configures the elements of the phased array antenna according to the scaling using adaptive interference rejection. The gateway station has an adaptive beam processor coupled to user position files. The adaptive beam processor with the user position data can adaptively cancel interference from other beams.

6914557, Jul 5, 2005

Sep 5, 2001

09/947422

Donald C. D. Chang - Thousand Oaks CA, US
Ying Feria - Manhattan Beach CA, US
Weizheng Wang - Rancho Palos Verdes CA, US
Alan G. Cha - Glendale CA, US
Ming U. Chang - Rancho Palos Verdes CA, US
Frank A. Hagen - Palos Verdes Estates CA, US
Kar W. Yung - Torrance CA, US

The DIRECTV Group, Inc. - El Segundo CA

H04B007/185

342354

A system and method for tracking a user. The system is adapted for use in a wireless communication system and creates a plurality of beams within a coverage area. A first beam is directed at a user in a first microcell and a number of additional beams illuminate microcells immediately adjacent the first microcell. The system is equipped with a mechanism for detecting movement of the user from the first microcell to one of the immediately adjacent microcells. On the detection of movement of the user, the system redirects the first beam from the first microcell to a second microcell, the second microcell being one of the adjacent microcells. In the illustrative embodiment, the system is implemented in a stratospheric platform based communication system including a hub adapted to communicate with a stratospheric platform. A transceiver and a phased array antenna are disposed on the platform to communicate with the hub and with the user. A second antenna is provided on the platform to communicate with the hub.

6941138, Sep 6, 2005

Sep 5, 2000

09/655498

Donald C. D. Chang - Thousand Oaks CA, US
Alan Cha - Glendale CA, US

The DIRECTV Group, Inc. - El Segundo CA

H04Q007/20

455427, 455 121, 455430, 455431

A method for communicating between a user terminal and multiple stratospheric transponder platforms includes the steps of positioning a plurality of stratospheric transponder platforms () in a substantially fixed position () with respect to a user terminal antenna () coupled to a user terminal () and communicating between the user terminal () and at least two of the plurality of stratospheric transponder platforms () concurrently.