Patents by Inventor Shih-Fong Chao

Shih-Fong Chao 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).

  • Switchable bandpass filter having stepped-impedance resonators loaded with diodes
    Patent number: 8044751
    Abstract: A switchable bandpass filter includes a first stepped-impedance resonator, a second stepped-impedance resonator wirelessly coupled to the first stepped-impedance resonator, and a first diode connected to one end of the second stepped-impedance resonator.
    Type: Grant
    Filed: July 18, 2008
    Date of Patent: October 25, 2011
    Assignee: National Taiwan University
    Inventors: Zuo-Min Tsai, Shih-Fong Chao, Huei Wang
  • Single-pole-double-throw switch integrated with band pass filtering function
    Patent number: 7659794
    Abstract: A single-pole-double-throw switch is provided, which is configured to be integrated with a bandpass filtering function and includes four quarter-wavelength transmission lines connected in series, five resonators connected in parallel to each other, and four transistors connected in parallel to four of the five resonators. When two of the four transistors are turned on and the others are turned off, the single-pole-double-throw switch is equivalent to a third-order quarter-wavelength short-circuited stub bandpass filter.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: February 9, 2010
    Assignee: National Taiwan University
    Inventors: Zuo-Min Tsai, Shih-Fong Chao, Huei Wang
  • Switchable bandpass filter having stepped-impedance resonators loaded with diodes
    Publication number: 20100013576
    Abstract: A switchable bandpass filter includes a first stepped-impedance resonator, a second stepped-impedance resonator wirelessly coupled to the first stepped-impedance resonator, and a first diode connected to one end of the second stepped-impedance resonator.
    Type: Application
    Filed: July 18, 2008
    Publication date: January 21, 2010
    Applicant: National Taiwan University
    Inventors: Zuo-Min Tsai, Shih-Fong Chao, Huei Wang
  • Power amplifier having input ends combined in series and output ends combined in series
    Patent number: 7598810
    Abstract: A power amplifier includes a first transformer, a first transistor, a first resistor, a second transformer, a second transistor, a second resistor, and a bias circuit. The first transformer drives the first transistor. The second transformer drives the second transistor. The first transformer is connected in series with the second transformer. The first transistor is connected in series with the second transistor. Therefore, the power amplifier has input impedance and output power both greater than those of a conventional power amplifier.
    Type: Grant
    Filed: June 5, 2008
    Date of Patent: October 6, 2009
    Assignee: National Taiwan University
    Inventors: Shih-Fong Chao, Zuo-Min Tsai, Huei Wang
  • POWER AMPLIFIER HAVING INPUT ENDS COMBINED IN SERIES AND OUTPUT ENDS COMBINED IN SERIES
    Publication number: 20090115529
    Abstract: A power amplifier includes a first transformer, a first transistor, a first resistor, a second transformer, a second transistor, a second resistor, and a bias circuit. The first transformer drives the first transistor. The second transformer drives the second transistor. The first transformer is connected in series with the second transformer. The first transistor is connected in series with the second transistor. Therefore, the power amplifier has input impedance and output power both greater than those of a conventional power amplifier.
    Type: Application
    Filed: June 5, 2008
    Publication date: May 7, 2009
    Applicant: NATIONAL TAIWAN UNIVERSITY
    Inventors: Shih-Fong Chao, Zuo-Min Tsai, Huei Wang
  • SINGLE-POLE-DOUBLE-THROW SWITCH INTEGRATED WITH BAND PASS FILTERING FUNCTION
    Publication number: 20090115550
    Abstract: A single-pole-double-throw switch is provided, which is configured to be integrated with a bandpass filtering function and includes four quarter-wavelength transmission lines connected in series, five resonators connected in parallel to each other, and four transistors connected in parallel to four of the five resonators. When two of the four transistors are turned on and the others are turned off, the single-pole-double-throw switch is equivalent to a third-order quarter-wavelength short-circuited stub bandpass filter.
    Type: Application
    Filed: June 5, 2008
    Publication date: May 7, 2009
    Applicant: NATIONAL TAIWAN UNIVERSITY
    Inventors: Zuo-Min Tsai, Shih-Fong Chao, Huei Wang