Patents by Inventor Dow-Chih Niu

Dow-Chih Niu 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: 7064611
    Abstract: A single-power-supply Idss-bias RF amplifier is disclosed, which is composed by the first and second stages Amplifiers. The two stages have the same circuit topology except matching circuits. The source terminal of amplifier is grounded directly to reduce a parasitic effect from a bias circuit. It will increase the stability of the RF amplifier and avoid an oscillation. The lossy matching circuits and eliminating resonator circuit are designed to make the RF amplifier unconditional stable. A variable resister is put into to adjust a D.C. voltage on the drain terminal. The current of amplifier could be controlled in a reasonable range. High gain and quit low noise have been obtained.
    Type: Grant
    Filed: January 8, 2004
    Date of Patent: June 20, 2006
    Assignee: Chung-Shan Institute of Science and Technology
    Inventors: Dow-Chih Niu, Chia-Yang Chen
  • Publication number: 20060038632
    Abstract: A series-parallel resonant matching circuits and a broadband power amplifier thereof are disclosed. The series-parallel resonant matching circuit is connected to the last power transistor and the next power transistor. The series-parallel resonant matching circuit comprises a series matching inductor, a parallel matching inductor and an impedance transformation unit. The impedance transformation unit is connected between the series matching inductor and the intrinsic parallel matching inductor for transforming impedance. The parallel matching inductor and the parallel capacitor of a last level power transistor constitute a LC parallel resonant circuit, the series matching inductor and the series intrinsic capacitor of a next level power transistor constitute a LC series resonant circuit. Besides, the intrinsic parallel capacitance is a drain-to-source capacitor for the power transistor. The intrinsic series capacitance is a gate-to-source capacitor for the power transistor.
    Type: Application
    Filed: August 20, 2004
    Publication date: February 23, 2006
    Inventors: Dow-Chih Niu, Hao-Jung Li, Yuen-Shiang Huang
  • Patent number: 6995635
    Abstract: The parallel-coupled-resonator coupled line filter with open-and-short end, comprises an input port for receiving an input signal; a bent first resonator and a bent third resonator where their both ends are open circuited; a second resonator whose both ends are shorted to ground; and an output port for outputting signal. Wherein, designing cross coupling between the third resonator and the first resonator to obtain a steep frequency response and reduce the interference of the image signal.
    Type: Grant
    Filed: February 26, 2004
    Date of Patent: February 7, 2006
    Assignee: Chung Shan Institute of Science and Technology
    Inventors: Hong-long Wung, Chi-Yang Chang, Dow-Chih Niu
  • Publication number: 20050190016
    Abstract: The parallel-coupled-resonator coupled line filter with open-and-short end, comprises an input port for receiving an input signal; a bent first resonator and a bent third resonator where their both ends are open circuited; a second resonator whose both ends are shorted to ground; and an output port for outputting signal. Wherein, designing cross coupling between the third resonator and the first resonator to obtain a steep frequency response and reduce the interference of the image signal.
    Type: Application
    Filed: February 26, 2004
    Publication date: September 1, 2005
    Inventors: Hong-Iong Wung, Chi-Yang Chang, Dow-Chih Niu
  • Publication number: 20040201424
    Abstract: A single-power-supply Idss-bias RF amplifier is disclosed, which is composed by the first and second stages Amplifier. The two stages have the same circuit topology except the matching circuits. The source terminal of amplifier is grounded directly to reduce the parasitic effect from the bias circuit. It will increase the stability of the RF amplifier and avoid the oscillation. The lossy matching circuits and eliminating resonator circuit are designed to make the RF amplifier unconditional stable. A variable resister is put into to adjust the D.C. voltage on drain terminal. The current of amplifier could be controlled in reasonable range. High gain and quit low noise have been obtained.
    Type: Application
    Filed: January 8, 2004
    Publication date: October 14, 2004
    Inventors: Dow-Chih Niu, Chia-Yang Chen
  • Patent number: 6531943
    Abstract: A balun-transformer, which is composed of a balun transition and an impedance matching circuit. Chemical etching is employed in the manufacturing process that is compatible with the common microwave circuit manufacturing process. Using the odd mode analysis and commercial microwave software to design the balun-transformer. It is more accurate and more efficient than the conventional method to make balun-transformer that it can only be designed by experience and experiments. These balun-transformers can be used in UHF and VHF band.
    Type: Grant
    Filed: April 20, 2001
    Date of Patent: March 11, 2003
    Assignee: Chung Shan Institute of Science and Technology
    Inventors: Dow-Chih Niu, Chi-Yang Chang, Lih-Shiang Lin
  • Publication number: 20020153984
    Abstract: A balun-transformer, which is composed of a balun transition and an impedance matching circuit. Chemical etching is employed in the manufacturing process that is compatible with the common microwave circuit manufacturing process. Using the odd mode analysis and commercial microwave software to design the balun-transformer, It is more accurate and more efficient than the conventional method to make balun-transformer that it can only be designed by experience and experiments. These balun-transformers can be used in UHF and VHF band.
    Type: Application
    Filed: April 20, 2001
    Publication date: October 24, 2002
    Inventors: Dow-Chih Niu, Chi-Yang Chang, Lih-Shiang Lin