(19)

(11)

EP 1 634 369 A1

(12)

(43) Date of publication: 15.03.2006 Bulletin 2006/11 (21) Application number: 04736648.9 (22) Date of filing: 11.06.2004

(51) International Patent Classification (IPC):  H03F 1/06(1968.09) H03F 1/56(1980.01) H03F 1/32(1968.09) H03F 3/191(1974.07) (86) International application number: PCT/GB2004/002469 (87) International publication number: WO 2004/112237 (23.12.2004 Gazette 2004/52)

(84) Designated Contracting States: AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LI LU MC NL PL PT RO SE SI SK TR (30) Priority: 13.06.2003 GB 0313781 (71) Applicant: Sepura Limited Cambridge CB4 1GR (GB)	(72) Inventor: CULLING, Dennis Cambridge CB4 1FD (GB) (74) Representative: Tothill, John Paul  Frank B. Dehn & Co. 179 Queen Victoria Street London EC4V 4EL London EC4V 4EL (GB)