(19)

(11)

EP 1 019 978 A1

(12)

(43) Date of publication: 19.07.2000 Bulletin 2000/29 (21) Application number: 97945171.3 (22) Date of filing: 12.06.1997

(51) International Patent Classification (IPC)7: H01Q 1/12, H01Q 1/28 (86) International application number: PCT/US9709/850 (87) International publication number: WO 9857/388 (17.12.1998 Gazette 1998/50)

(84) Designated Contracting States: ES FR GB GR IT SE (71) Applicant: Northrop Grumman Corporation Los Angeles,California 90067-2199 (US)	(72) Inventor: ENG, Norman Commack, NY 11725 (US) (74) Representative: Maury, Richard Philip et al Sommerville & Rushton,45 Grosvenor Road St. Albans, Herts AL1 3AW St. Albans, Herts AL1 3AW (GB)