(19)

(11)

EP 0 527 178 A1

(12)

(43) Date of publication: 17.02.1993 Bulletin 1993/07 (21) Application number: 91908681.0 (22) Date of filing: 29.04.1991

(51) International Patent Classification (IPC):  H01Q 13/ 20( . ) H01Q 21/ 06( . ) H01Q 13/ 22( . ) (86) International application number: PCT/AU1991/000165 (87) International publication number: WO 1991/017586 (14.11.1991 Gazette 1991/26)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 30.04.1990 AU 19900009878 (71) Applicant: COMMONWEALTH SCIENTIFIC & INDUSTRIAL RESEARCH ORGANISATION ( C.S.I.R.O. ) Campbell ACT 2601 (AU)	(72) Inventor: POULTON, Geoffrey, Thomas Westleigh, NSW 2120 (AU) (74) Representative: Senior, Alan Murray, et al  J.A. KEMP & CO., 14 South Square, Gray's Inn London WC1R 5LX London WC1R 5LX (GB)