Patents by Inventor Hien Duc Ma

Hien Duc Ma has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6563805
    Abstract: A device for prepaid recording of digital audio signals. In a system where digital radio signals are received in an encoded format, a digital converter that is enabled by a smartcard module is employed to convert encoded digital signals to decoded digital signals for recording onto a digital storage media. A smartcard having a prepaid account balance is employed to authorize and control the recording of digital signals. A buffer is advantageously employed to store a quantity of digital signals prior to recording.
    Type: Grant
    Filed: November 5, 1999
    Date of Patent: May 13, 2003
    Assignee: XM Satellite Radio, Inc.
    Inventors: Hien Duc Ma, Argyrios A. Chatzipetros
  • Patent number: 6232926
    Abstract: A dual coupled vehicle glass mount antenna system and method. The inventive system is adapted for operation through any suitable partition, such as an automobile windshield, and comprises an antenna mounted on a first side of the partition for receiving a signal and a first circuit connected to the antenna. The antenna and the first circuit are mounted on a first side of the partition. In accordance with the present teachings, an arrangement is provided for supplying power to the first circuit. The output of the first circuit is coupled through the partition to a second circuit mounted on a second side thereof by a first coupling arrangement. In the illustrative embodiment, the antenna is a radio frequency antenna, the partition is a vehicle windshield, the first circuit is an amplifier, and the arrangement for supplying power is a second coupling arrangement.
    Type: Grant
    Filed: November 10, 1999
    Date of Patent: May 15, 2001
    Assignee: XM Satellite Radio Inc.
    Inventors: Anh Nguyen, Argyrios A. Chatzipetros, Hien Duc Ma