Claims
- 1. An antenna comprising:
- a coplanar array of dipoles tuned to electromagnetic signals of a given wavelength .lambda. and arranged with respect to orthogonal first, second and third directions in rows extending in the first direction and columns extending in the second direction,
- a ground plane parallel to said first and second directions, each dipole being spaced in the third direction from said ground plane and having two poles which are aligned in the first direction, and
- a plurality of individual parasitic conductive posts respectively disposed in the rows, the posts extending from said ground plane in said third direction a distance no greater than .lambda./4 and being positioned so as to separate adjacent dipoles in each row, thereby to reduce mutual coupling between said dipoles, said posts having a length in said second direction which is less than .lambda./2.
- 2. An antenna according to claim 1, further including a beam scanning means connected to said dipoles for controlling the relative phases of energy fed to different dipoles so as to scan a direction of maximum gain of said antenna.
- 3. An antenna as in claim 1, further comprising means for applying a signal of given frequency to said dipoles, said posts having lengths in said third direction tuned for said given frequency to minimize mutual coupling.
- 4. An antenna as in claim 1, wherein said posts have a length in said second direction which is less than .lambda./4.
- 5. An antenna comprising:
- an array of dipoles tuned to electromagnetic signals of a given wavelength .lambda. and disposed in an array plane, and arranged with respect to orthogonal first, second and third directions in rows extending in the first direction and columns extending in the second direction, each dipole having two poles which are aligned in the first direction,
- a ground plane spaced in said third direction from said array plane, and
- a plurality of separate parasitic, conductive posts respectively disposed in the rows, said posts extending from said ground plane toward said array plane in said third direction a distance no greater than .lambda./4 and being positioned so as to separate adjacent dipoles in each row and form a means for absorbing and re-radiating at a low angle to said array plane some radiation emitted by said dipoles, thereby to reduce mutual coupling between said dipoles, said posts having a length in said second direction which is less than .lambda./2.
- 6. An antenna as in claim 5, further comprising beam scanning means connected to said dipoles for controlling relative phases of energy fed to different ones of said dipoles so as to scan a direction of maximum gain of said antenna.
- 7. An antenna as in claim 5, further comprising means for applying a signal of given frequency to said dipoles, said posts having lengths in said third direction tuned for said given frequency to minimize mutual coupling.
- 8. An antenna as in claim 5, wherein said posts have a length in said second direction which is less than .lambda./4.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8432186 |
Dec 1984 |
GBX |
|
8523076 |
Sep 1985 |
GBX |
|
Parent Case Info
This application is a continuation of application Ser. No. 07/241,787 filed Sept. 6th, 1988, now abandoned, which is a continuation-in-part of application Ser. No. 06/810,275 filed Dec. 18th, 1985, now abandoned.
US Referenced Citations (10)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0048190 |
Mar 1982 |
EPX |
2123215 |
Jan 1984 |
GBX |
2135829 |
Sep 1984 |
GBX |
Continuations (1)
|
Number |
Date |
Country |
Parent |
241787 |
Sep 1988 |
|
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
810275 |
Dec 1985 |
|