(19)
(11) EP 0 430 489 A3

(12) EUROPEAN PATENT APPLICATION

(88) Date of publication A3:
01.04.1992 Bulletin 1992/14

(43) Date of publication A2:
05.06.1991 Bulletin 1991/23

(21) Application number: 90312412.1

(22) Date of filing: 14.11.1990
(51) International Patent Classification (IPC)5: H01P 5/10
(84) Designated Contracting States:
AT BE CH DE DK ES FR GR IT LI LU NL SE

(30) Priority: 17.11.1989 GB 8926040

(71) Applicant: THE MARCONI COMPANY LIMITED
Stanmore Middlesex HA7 4LY (GB)

(72) Inventor:
  • Burrage, Clement Peter
    Braintree, Essex, CM7 8QD (GB)

(74) Representative: Loven, Keith James et al
GEC Patent Department, GEC Marconi Limited, West Hanningfield Road
Great Baddow Chelmsford, Essex CM2 8HN
Great Baddow Chelmsford, Essex CM2 8HN (GB)


(56) References cited: : 
   
       


    (54) Broadband balun


    (57) A broadband balun, comprises first and second tubular conductors (1, 2) arranged substantially parallel, the first tubular conductor (1) being open at both ends and the second tubular conductor (2) being closed at one end. Each tubular conductor is grounded, the second (2) at its closed end and the first (1) at its end adjacent thereto. An input conductor (3) passes through the first tube (1) and back through the second tube (2) to terminate close to but spaced from the closed end thereof. And parallel pair of output conductors (4, 5) each connect to a respective one of the tubular conductors (1, 2) at the end thereof remote from the grounded end. Impedances may be selected to permit the balun to operate over a broad range of frequencies, e.g. 6 to 24MHz, without the need for adjustment or tuning.







    Search report