| (19) |
 |
|
(11) |
EP 0 421 757 A3 |
| (12) |
EUROPEAN PATENT APPLICATION |
| (88) |
Date of publication A3: |
|
21.11.1991 Bulletin 1991/47 |
| (43) |
Date of publication A2: |
|
10.04.1991 Bulletin 1991/15 |
| (22) |
Date of filing: 03.10.1990 |
|
| (51) |
International Patent Classification (IPC)5: H01Q 13/02 |
|
| (84) |
Designated Contracting States: |
|
DE FR IT |
| (30) |
Priority: |
04.10.1989 GB 8922377
|
| (71) |
Applicant: GEC-MARCONI LIMITED |
|
Stanmore,
Middlesex HA7 4LY (GB) |
|
| (72) |
Inventor: |
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- Jairam, Hari
Harrow,
Middlesex HA3 7NA (GB)
|
| (74) |
Representative: Waters, Jeffrey |
|
The General Electric Company, p.l.c.
GEC Patent Department
Waterhouse Lane
Chelmsford, Essex CM1 2QX
Chelmsford, Essex CM1 2QX (GB) |
|
| |
|
(57) A microwave horn antenna providing wide beam-width of approximately 95 degrees over
a band width of 8 to 18GHZ. The antenna consists of a radiating cylinder (1) the front
end of which is shaped to provide a central apex or ridge (6) with two faces sloping
back from it. A conductor wire (5) extends to provide this ridge across the cylinder
(1). Further matching wires (9, 11) extend across behind the ridge conductor (5).
A choke ring (19) surrounds the radiating aperture, consisting of a plurality of concentric
channels (21) of graded depth, this being one quarter wavelength at frequencies throughout
the band. A wide beam, broad band antenna of high performance is thus provided.