Title:
ANTENNA SYSTEM
Document Type and Number:
Japanese Patent JP2950459
Kind Code:
B2
Abstract:
PURPOSE: To easily obtain high gain and broad band characteristic and to eliminate the effect of an installed object by employing a coaxial impedance converter to form a slot antenna.
CONSTITUTION: In order to match the impedance of a feeder 24 with the antenna impedance when a 1/2 wavelength antenna element 21 fed from its lower end, the antenna system is provided with a coaxial impedance converter 22, the characteristic impedance of the feeder 24 is selected to be the geometric means of sets of the impedance and a 1/4 wavelength is selected for the length of the converter 22. Thus, the impedance of the converter 22 is matched with the impedance of the antenna element 21 by converting the impedance with the converter 22. On the other hand, a capacitor 29 is provided in resonance with the inductive component depending on the length of a slit 26 at an operating wavelength and an outer conductor 25 acts like the impedance converter with respect to the element 21, and the slit 26 acts like a slot antenna 27 and the space is shared in common. Since the converter 22 is broad in band and is not a matching circuit using a lumped constant, then the loss is small. Moreover, since a coaxial structure has a stub effect, the effect of other installed objects is less.
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Inventors:
TSUNEKAWA KOICHI
HAGIWARA SEIJI
HAGIWARA SEIJI
Application Number:
JP1513494A
Publication Date:
September 20, 1999
Filing Date:
February 09, 1994
Export Citation:
Assignee:
ENU TEI TEI IDO TSUSHINMO KK
International Classes:
H01Q3/24; H01Q1/24; H01Q1/36; H01Q13/10; H01Q21/28; (IPC1-7): H01Q21/28; H01Q1/24
Domestic Patent References:
| JP62213303A | ||||
| JP5235628A | ||||
| JP63290417A |
Attorney, Agent or Firm:
Kusano Taku (1 person outside)