Communications: directive radio wave systems and devices (e.g. – Directive – Including a steerable array
Patent
1992-10-09
1993-10-26
Hellner, Mark
Communications: directive radio wave systems and devices (e.g.,
Directive
Including a steerable array
343909, H01Q 302
Patent
active
052570312
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
This invention concerns a multibeam antenna which has a high switching capability with high RF power levels. It relates to the field of electronically switched beam antennas. The invention may find application in the field of electronic defence systems by handling single or multiple threats arriving from different directions.
The antenna can provide pseudo adaptability to the radar cross section, as it is made up of three subarrays, each of which includes eight elementary equispaced radiators which assure angular coverage of the azimuth hemispace from 0.degree. to 180.degree., fed by a single beamshaping network which provides the correct field amplitude and phase distribution.
The hemispace is therefore divided into-three angular sectors, with each of which a subarray is associated. Switching between these angular sectors and within each sector is electronic.
Each subarray, as mentioned above, shapes three beams which take different angular positions on the azimuth plane through the same feed network. The selection of these beams is electronic upon designation by the system which assesses relevant direction of arrival. One of the previous solutions was to utilize arrays fed by Rothman lenses or by Butler matrixes. Another solution was provided by a series of directional antennas, one for each beam to shape, fed by an n-way switch (as many ways as the number of beams) or by transmitters.
These solutions have a number of drawbacks, among them: dimension increase; involved.
SUMMARY OF THE INVENTION
The antenna, which is the subject of this invention, consists of three subarrays (5), (6), (7) which suitably spaced, can assure angular coverage in the 0.degree.-180.degree. azimuth hemispace. (In a specular manner, three more subarrays, fed by a separate transmitter, can assure angle coverage in the other 180.degree.-360.degree. azimuth hemispace). The three subarrays are fed by a single beamforming network which provides for the correct field amplitude and phase distribution to each subarray.
The hemispace is thus divided into three angle sectors, to each one of which a subarray is associated.
Switching between these angular sectors is performed electronically and within each sector; the relevant subarray forms three beams which take different angle directions on the azimuth plane through the same feed network.
Selection of these beams is in turn electronic, upon indication from the designating system, i.e. the system which descerns the direction of arrival of the threat or threats. The beam switching and forming network consists of solid state components to obtain the high switching speeds (100-150 nsec) which are required to satisfy the tasks demanded of the system. The gain of each beam, required to established the necessary effective radiated power, is achieved by providing the array with a directivity also in the vertical plane.
This can be achieved by using as an element of the array a sectorial horn radiator, over the aperture of which a phase correcting dielectric lens is placed, which enhances radiation efficiency. A most interesting characteristic of this indicating system is that of directing the beam to the desired direction in negligible times. This is achieved through: each having a 0.degree. to 180.degree. coverage sector;
This gives the antenna system the capability of handling multiple threats.
The transmitting antenna is made up of two specular subassemblies each covering a 180.degree. sector.
It may be installed, in its preferred configuration, on board a ship (FIG. 1).
BRIEF DESCRIPTION OF THE DRAWINGS
To facilitate further discussion of the present invention, the following drawings are provided in which:
FIG. 1 shows a schematic representation of the antenna portion of the system as installed on board a ship;
FIG. 1A shows an enlarged view of the antenna portion indicated in FIG. 1;
FIG. 2 shows a functional schematic diagram of the antenna system;
FIG. 3 shows a block diagram of the antenna system showing angular coverage of the three subarrays;
FIG. 4 sh
REFERENCES:
patent: 3101472 (1963-08-01), Goubau
patent: 3430249 (1969-02-01), Franks
patent: 3755815 (1973-08-01), Stangel et al.
patent: 3816830 (1974-06-01), Giannini
patent: 4124852 (1978-11-01), Steudel
patent: 4156878 (1979-05-01), Dion
patent: 4178574 (1979-12-01), Edens et al.
patent: 4186398 (1980-01-01), Minnett et al.
patent: 4257050 (1981-03-01), Ploussios
patent: 4321604 (1982-03-01), Ajioka
patent: 4451831 (1984-05-01), Stangel et al.
patent: 4489325 (1984-12-01), Bauck et al.
G. Seehausen, "Feed System for Spherical Antenna Arrays with Amplitude Control", Conference Proceedings of 12th European Microwave Conference, Sep. 13-17, 1982, Helsinki, Finland, at pp. 661-666.
Article entitled "An Airborne Electronically Scanned X Band Narrow Beam Circular Antenna Array," by R. H. J. Cary, in IEEE Conference on Aerospace Antennas, Jun. 8-10, 1971, London, England, at pp. 19-24.
H. Jasik (ed.), Antenna Engineering Handbook, pp. 13-14, 14-2, and 14-3 (1st ed. 1951).
Russo Pasquale
Scarpetta Rosario
Cave Bryan
Hellner Mark
Selenia - Industrie Elettroniche Associate - S.p.A.
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