(19)
(11) EP 0 921 590 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
15.09.1999 Bulletin 1999/37

(43) Date of publication A2:
09.06.1999 Bulletin 1999/23

(21) Application number: 98309924.3

(22) Date of filing: 03.12.1998
(51) International Patent Classification (IPC)6: H01Q 3/20, H01Q 19/13
(84) Designated Contracting States:
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE
Designated Extension States:
AL LT LV MK RO SI

(30) Priority: 04.12.1997 JP 33406097

(71) Applicant: NEC CORPORATION
Tokyo (JP)

(72) Inventors:
  • Yamamoto, Osamu
    Minato-ku, Tokyo (JP)
  • Iwata, Ryuichi
    Minato-ku, Tokyo (JP)

(74) Representative: Moir, Michael Christopher et al
Mathys & Squire 100 Gray's Inn Road
London WC1X 8AL
London WC1X 8AL (GB)

   


(54) Antenna for communicating with low earth orbit satellite


(57) To provide an antenna for communicating with a low earth orbit (LEO) satellite which is small-sized and light and can track a LEO satellite at high speed at a small-sized earth station using a LEO satellite, the above antenna uses an offset parabolic antenna-type reflector and a primary feed is installed in the focal position of the paraboloid of revolution forming the reflector. The quantity of an offset of the offset parabolic antenna is selected so that antenna gain is maximum at the minimum operational elevation. The primary feed is mechanically independent of the mobile reflector and is attached and fixed to a radiator supporting part. The reflector is turned based upon an azimuth axis and an elevation axis according to AZ-EL mount.






Search report