Communications: radio wave antennas – Antennas – Wave guide type
Reexamination Certificate
1998-10-06
2001-02-27
Phan, Tho (Department: 2821)
Communications: radio wave antennas
Antennas
Wave guide type
C343S779000, C343S872000, C455S351000
Reexamination Certificate
active
06195061
ABSTRACT:
FIELD OF INVENTION
This invention relates to horn antennas, and more particularly to a skewed beam sectoral horn antenna.
BACKGROUND OF INVENTION
In order for an antenna to be effective, it must radiate electromagnetic energy efficiently. That is to say, it must radiate as much energy as possible at the desired frequency, in the desired direction across the desired bandwidth. While antennas can be made to meet these requirements, they often are very expensive to manufacture due to the materials required and the labor necessary to produce them. The size of the antenna also plays an important role in determining which antennas are suited for a particular application. For example, when the application includes an anticipatory collision detection system which operates in the C-band range (4 GHz to 8 GHz) and must be located in the bumper of an automobile, size becomes critical while still maintaining the appropriate beam width and band width. A typical symmetrical horn antenna operating in this range is in excess of one foot in length.
One possible antenna for such an application is a two element patch array. However, this antenna is expensive to manufacture because it requires: expensive microwave materials, a separate printed circuit board which includes an antenna, and a special cover which must be custom tuned very accurately. The antenna must be oriented vertically to produce the desired radiation pattern in the appropriate direction limiting the placement and mounting of the antenna. Even then the beam width is well under 100°, requiring multiple antenna sections to produce a usable beam width. Moreover, the usable band width is less than 100 MHz. Thus, this antenna requires multiple manufacturing steps, expensive materials and labor, and yields less than favorable mounting, beam width and band width characteristics.
Another antenna includes the printed circuit dipole or microstrip dipole which has circuits etched on a printed circuit board which is then soldered perpendicularly to the printed circuit board containing the electronics. This results in a flimsy non-rigid structure which also requires a special cover, expensive manufacturing materials and multiple, expensive manufacturing steps to produce and assemble. This structure, like the previous antenna, suffers from similar shortcomings such as a narrow band width, a narrow beam width and a particular orientation which still produces a less than suitable radiation pattern. A typical band width is less than 100 MHz and the beam width is less than 100°. Moreover, this antenna produces high side lobes which, in the case of an anticipatory collision detection system, illuminates the ground increasing system noise, thereby increasing the chance of errors.
SUMMARY OF INVENTION
It is therefore an object of this invention to provide a miniature horn antenna which is small in size and cost effective to manufacture.
It is a further object of this invention to provide such an antenna where the electronics housing forms the antenna.
It is a further object of this invention to provide such an antenna which produces a beam width of approximately 180°.
It is a further object of this invention to provide such an antenna which is operable over a band width of over 300 MHz.
It is a further object of this invention to provide such an antenna which is less sensitive to tuning parameters.
It is a further object of this invention to provide such an antenna which can be adjusted to vary the beam tilt to accommodate various mounting positions.
It is a further object of this invention to provide such an antenna which radiates forward regardless of its physical orientation.
The invention results from the realization that a truly efficient and cost effective miniature horn antenna can be achieved by using the electronics housing to form a skewed beam sectoral horn by defining a rear wall, side wall and two divergent wall and placing the feed probe in front of the rear wall and between the divergent walls to eliminate the waveguide portion of the antenna.
The invention features a miniature horn antenna having a housing forming a skewed beam sectoral horn. The housing forms first and second divergent walls having a primary axis in which at least one of the first and second divergent walls is transverse to the primary axis, a rear wall joining the first and second divergent walls, and a first side wall. There is a feed probe in front of the rear wall and between the first and second divergent walls and a second side wall.
In a preferred embodiment, the feed probe may be capacitively coupled with the housing. The feed probe may extend through one of the first or second side walls and may have a flat end to capacitively couple the feed probe with the housing. The feed probe may have a conical shape, a cylindrical shape, or a disc shape. The feed probe may include a dielectric medium for capacitive coupling the feed probe with the housing. There may be a harmonic suppressor between the rear wall and the feed probe for minimizing radiation of a predetermined harmonic. The predetermined harmonic may include the second harmonic. There may be a tuning reflector parallel to one of the first or second divergent walls. The second side wall may be formed by the ground plane of a printed circuit board. The printed circuit board may include a microwave circuitry for providing electromagnetic energy to the feed probe. The other of the first and second divergent walls may be parallel to the primary axis.
The invention also features a miniature horn antenna includes a housing forming a skewed beam sectoral horn, the housing forming first and second divergent walls having a primary axis in which at least one of the first and second divergent walls is transverse to the primary axis, a rear wall joining the first and second divergent walls, and a first side wall. There is a feed probe in front of the rear wall and between the first and second divergent walls and a second side wall. There is a tuning reflector parallel to one of the first or second divergent walls.
In a preferred embodiment, the feed probe may be capacitively coupled with the housing. The feed probe may have a flat end to capacitively couple the feed probe with the housing. The feed probe may have a conical shape, a cylindrical shape, or a disc shape. The feed probe may include a dielectric medium for capacitive coupling the feed probe with the housing.
REFERENCES:
patent: 4482898 (1984-11-01), Dragone et al.
patent: 4613989 (1986-09-01), Fende et al.
patent: 4734660 (1988-03-01), Lofgren
patent: 5245353 (1993-09-01), Gould
patent: 5305000 (1994-04-01), Harris
Hizal Altunkan
Lyons Christopher T.
Hittite Microwave Corp.
Iandiorio & Teska
Phan Tho
Teska Kirk
LandOfFree
Miniature skewed beam horn antenna does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Miniature skewed beam horn antenna, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Miniature skewed beam horn antenna will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2605364