Patents by Inventor Satoru Shiratsuchi

Satoru Shiratsuchi 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: 7671691
    Abstract: A quadrature modulator divides a first signal input as a local signal into an I channel signal and a Q channel signal orthogonal to each other and outputs a second signal having a desired phase delay corresponding to direct current voltages as for the first signal by giving the direct current voltages Vi and Vq to the I channel signal and the Q channel signal, respectively. A phase comparison unit detects a phase difference ? between the first signal and the second signal. A setting unit sets the desired phase delay. A controller section controls the direct current voltages supplied to the I channel signal and the Q channel signal respectively in the quadrature modulator so that an output value corresponding to the phase difference ? detected by the phase comparison unit is equal to a value corresponding to the desired phase delay set by the setting unit, and controls the direct current voltages to be the direct current voltages Vi and Vq satisfying the relation of Vi=cos ? and Vq=sin ?.
    Type: Grant
    Filed: February 1, 2007
    Date of Patent: March 2, 2010
    Assignee: Anritsu Corporation
    Inventors: Satoru Shiratsuchi, Kazuhiro Fujinuma, Kazuhiko Yamaguchi
  • Patent number: 7613239
    Abstract: A digital signal offset adjusting apparatus has a capacitor causing an output terminal to pass a high frequency band of an input digital signal. A first coil has one end connected to an input terminal and a second coil has one end connected to an output. An operational amplifier has an input connected to another end of the first coil, a second input connected to a direct current voltage generator and an output connected to another end of the second coil. The operational amplifier outputs a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage. A frequency characteristic compensating circuit is connected between a reference point and the second input of the operational amplifier. The gain of the operational amplifier increases with a component having a higher frequency from among low frequency bands of the input digital signal.
    Type: Grant
    Filed: September 29, 2005
    Date of Patent: November 3, 2009
    Assignee: Anritsu Corporation
    Inventors: Satoru Shiratsuchi, Kazuhiro Fujinuma, Sumio Saito
  • Publication number: 20090140787
    Abstract: A quadrature modulator divides a first signal input as a local signal into an I channel signal and a Q channel signal orthogonal to each other and outputs a second signal having a desired phase delay corresponding to direct current voltages as for the first signal by giving the direct current voltages Vi and Vq to the I channel signal and the Q channel signal, respectively. A phase comparison unit detects a phase difference ? between the first signal and the second signal. A setting unit sets the desired phase delay. A controller section controls the direct current voltages supplied to the I channel signal and the Q channel signal respectively in the quadrature modulator so that an output value corresponding to the phase difference ? detected by the phase comparison unit is equal to a value corresponding to the desired phase delay set by the setting unit, and controls the direct current voltages to be the direct current voltages Vi and Vq satisfying the relation of Vi=cos ? and Vq=sin ?.
    Type: Application
    Filed: February 1, 2007
    Publication date: June 4, 2009
    Inventors: Satoru Shiratsuchi, Kazuhiro Fujinuma, Kazuhiro Fujinuma, Kazuhiko Yamaguchi
  • Publication number: 20070129903
    Abstract: A digital signal offset adjusting apparatus has a capacitor (21) causing an output terminal (20b) to pass through a high frequency band of an input digital signal in order to transmit a wideband digital signal without generating a waveform distortion, a first coil (23), one end of which is connected to an input terminal (20a), the first coil passing a low frequency band and a direct current component to another end, a second coil (22), one end of which is connected to an output end, a operational amplifier (31a), a first input end of which is connected to the other end of the first coil, a second input end of which is connected to a direct current voltage generator (25), an output end of which is connected to the other end of the second coil, the operational amplifier outputting to another end of the second coil a signal obtained by subtracting and combining the low frequency band, the direct current component and a direct current bias voltage, and a frequency characteristic compensating circuit (35) connecte
    Type: Application
    Filed: September 29, 2005
    Publication date: June 7, 2007
    Applicant: Anritsu Corporation
    Inventors: Satoru Shiratsuchi, Kazuhiro Fujinuma, Sumio Saito