Patents Assigned to DX Antenna Company, Ltd.
  • Patent number: 7486249
    Abstract: A radiator includes two dipole elements as plate-shaped conductors. The radiator further includes two conductive line portions provided on opposite sides of a prescribed axis, sandwiching both of the two dipole elements, each having one end connected to one dipole element and the other end connected to the other dipole element. The two conductive line portions are formed to conform to the shapes of the dipole elements. As the conductive line portions having such shapes are connected to the dipole elements, better characteristics can be attained over wide frequency range and the size can be made smaller than the conventional radiator. Thus, an antenna having smaller size and improved characteristics can be provided.
    Type: Grant
    Filed: November 21, 2006
    Date of Patent: February 3, 2009
    Assignee: DX Antenna Company, Ltd.
    Inventors: Toshio Fujita, Shingo Fujisawa
  • Patent number: 4794458
    Abstract: A modulation device especially suitable for use in a joint TV reception device for tuning the input video and audio signals to various TV channel frequencies. The device includes a modulator for modulating a carrier wave with the video and audio signals to provide a modulated signal, a mixer for mixing the modulated signal with a local oscillation signal to provide mixed signals, a wide band amplifier for amplifying the mixed signals and a variable low-pass filter for filtering the amplified mixed signals to provide a TV broadcasting signal of desired frequency. The device further includes a control device for controlling the frequency of the local oscillation signal and the cutoff frequency of the variable low-pass filter so as to cancel a higher harmonic component from the output signal to avoid undesirable inteference.
    Type: Grant
    Filed: August 14, 1987
    Date of Patent: December 27, 1988
    Assignee: DX Antenna Company, Ltd.
    Inventor: Akihiko Nagatomi
  • Patent number: 4788513
    Abstract: A device to be incorporated with a balanced modulator included in a sub-channel of a stereophonic modulator circuit for suppressing a subcarrier component remaining in the output signal of the balanced modulator. This device only includes a full-wave rectifier for rectifying the subcarrier and a mixer for subtractively mixing the output of the modulator with the rectified subcarrier wave, thereby effectively cancelling the remanent subcarrier component in very simple and economical fashion.
    Type: Grant
    Filed: October 22, 1987
    Date of Patent: November 29, 1988
    Assignee: DX Antenna Company, Ltd.
    Inventor: Tomoyuki Katayama
  • Patent number: D351154
    Type: Grant
    Filed: April 10, 1992
    Date of Patent: October 4, 1994
    Assignee: DX Antenna Company, Ltd.
    Inventor: Yoshio Fujino