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Antenna equipment

  • US 5,617,105 A
  • Filed: 09/23/1994
  • Issued: 04/01/1997
  • Est. Priority Date: 09/29/1993
  • Status: Expired due to Fees
First Claim
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1. An antenna equipment comprising:

  • a rod antenna element;

    a metal cylinder provided at one end of said rod antenna element and axially aligned therewith, said metal cylinder having a first predetermined length in its axial direction, said first predetermined length being an integral multiple of a quarter-wavelength;

    an inner conductor connected to one end of said rod antenna element and extended substantially along the center axis of said metal cylinder to form a coaxial line in combination therewith; and

    a feeder having a core conductor connected to said inner conductor and an outer conductor connected to said metal cylinder at one end thereof opposite from said rod antenna element;

    said coaxial line forming a coaxial impedance converter and said metal cylinder having a notch formed by cutting out a part of its periphery a second predetermined length in its axial direction from its marginal edge at the side of said rod antenna element, whereby impedance of said coaxial impedance converter is matched with said rod antenna element at first and second different frequencies, respectively.

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