Antenna-feeder device and antenna

• US 20060267852A1
• Filed: 11/28/2005
• Published: 11/30/2006
• Est. Priority Date: 05/31/2005
• Status: Active Grant

• Current Assignee: Jiho Ahn
• Original Assignee: Jiho Ahn
• Inventors: Davydov, Alexander, Ahn, Jiho, Bankov, Sergey
• Granted Patent: US 7,408,522 B2
• Time in Patent Office: Days
• US Class Current: 343/781.CA
• CPC Class Codes: H01Q 19/193 with feed supported subreflector splash plate feeds H01Q19/134
• CPC Class Codes: H01Q 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00

Abstract

An antenna comprises: a main reflector being a body of revolution of parabolic shape; a sub-reflector being a body of the revolution of elliptic shape having a circle and a vertex oriented to the main reflector and being placed between the circle and the main reflector, one focal point of the sub-reflector being placed on the axis of revolution and the other focal point of the sub-reflector being placed out of the axis, the sub-reflector circle being placed in the plane of the main reflector edge circle; a radiator being placed along the axis of revolution of the main reflector and being placed between the main reflector and the sub-reflector; and wherein the sub-reflector has eccentricity ranging from 0.55 to 0.75

Claims

1. An antenna comprising:

a main reflector being a body of revolution of parabolic shape;

a sub-reflector being a body of the revolution of elliptic shape having a circle and a vertex oriented to the main reflector and being placed between the circle and the main reflector, one focal point of the sub-reflector being placed on the axis of revolution and the other focal point of the sub-reflector being placed out of the axis;

a radiator being placed along the axis of revolution of the main reflector and being placed between the main reflector and the sub-reflector; and

wherein the sub-reflector has eccentricity ranging from 0.55 to 0.75

2. The antenna according to claim 1 further comprising the distance d between two focuses of the sub-reflector is selected under the following condition:

$,\frac{d}{\mathrm{\lambda <br><br>}}=\{\begin{array}{c}1.2-1.6<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}\le <br><br>12\\ 1.8-2.1<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>12\end{array}$

λ

is a free space wavelength

D is a diameter of the main reflector,

wherein angle β

between the line connecting the above focuses of the sub-reflector and axis of revolution is selected in range 45-70 degrees.

3. The antenna according to claim 1 further comprising the main reflector of parabolic shape which axis does not coincide with axis of the revolution

4. The antenna according to claim 1 further comprising the sub-reflector circle placed in the near plane of the main reflector edge circle

5. The antenna according to claim 1 further comprising a cover on which the sub-reflector circle is mounted.

6. The antenna according to claim 1 further comprising the circle of the sub-reflector which radius Er is selected under the following condition:

$\frac{E_r}{\mathrm{\lambda <br><br>}}=\{\begin{array}{c}0.5-1.2<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}\le <br><br>12\\ 1.5-1.8<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>12\end{array}$

where λ

is a free space wavelength, D is a diameter of the main reflector.

7. The antenna according to claim 1 further comprising the relation between radius of the focal ring of the sub-reflector and radius of the focal ring of the main reflector is selected under the following condition:

1.04≦

Fe2_r/F_r≦

1.6

where Fe2_r is focal ring radius of the sub-reflector second focus, F_r is focal ring radius of the main reflector.

8. The antenna according to claim 1 further comprising the relation between radius H_r of the radiator conical horn to free space wavelength is selected in the following range:

$0.6<<br><br>\frac{H_r}{\mathrm{\lambda <br><br>}}<<br><br>1.1,$

and the conical horn flare angle α

is selected under the following condition;

$\mathrm{\alpha <br><br>}=\{\begin{array}{c}25-{60}^0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>8\\ 70-{110}^0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}<<br><br>8\end{array}$

9. An antenna comprising:

a main reflector being a body of revolution of parabolic shape;

a sub-reflector being a body of the revolution of elliptic shape having a circle and a vertex oriented to the main reflector and being placed between the circle and the main reflector, one focal point of the sub-reflector being placed on the axis of revolution and the other focal point of the sub-reflector being placed out of the axis;

a radiator being placed along the axis of revolution of the main reflector and being placed between the main reflector and the sub-reflector; and

wherein the relation between radius of the focal ring of the sub-reflector second focus placed out of the axis and radius of the focal ring of the main reflector is selected under the following condition;

1.08≦

Fe2_r/F_r≦

1.5

where Fe2_r is focal ring radius of the sub-reflector second focus placed out of the axis, Fr is focal ring radius of the main reflector.

10. The antenna according to claim 9 further comprising the sub-reflector of eccentricity ranging from 0.55 to 0.75

11. The antenna according to claim 9 further comprising the distance d between two focuses of the sub-reflector is selected under the following condition:

$\frac{d}{\mathrm{\lambda <br><br>}}=\{\begin{array}{c}1.2-1.6<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}\le <br><br>12\\ 1.8-2.1<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>12\end{array},$

λ

is a free space wavelength

D is a diameter of the main reflector,

wherein angle β

between the line connecting the above focuses of the sub-reflector and axis of revolution is selected in range 45-70 degrees.

12. The antenna according to claim 9 further comprising the main reflector of parabolic shape which axis does not coincide with axis of the revolution

13. The antenna according to claim 9 further comprising the circle of the sub-reflector which radius Er is selected under the following condition:

$\frac{E_r}{\mathrm{\lambda <br><br>}}=\{\begin{array}{c}0.5-1.2<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}\le <br><br>12\\ 1.5-1.8<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>12\end{array}$

where λ

is a free space wavelength, D is a diameter of the main reflector.

14. The antenna according to claim 9 further comprising the relation between radius H_r of the radiator conical horn to free space wavelength is selected in the following range:

$0.6<<br><br>\frac{H_r}{\mathrm{\lambda <br><br>}}<<br><br>1.1,$

and the conical horn flare angle α

is selected under the following condition;

$\mathrm{\alpha <br><br>}=\{\begin{array}{c}25-{60}^0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}><br><br>8\\ 70-{110}^0<br><br>\text{\hspace{1em}<br><br>}<br><br>\mathrm{when}<br><br>\text{\hspace{1em}<br><br>}<br><br>\frac{D}{\mathrm{\lambda <br><br>}}<<br><br>8\end{array}$

15. An antenna-feeder device comprising:

four antennas situated in one plane;

a feeding device on the base of dividers wherein each divider consists of a junction of single-mode transmission lines and each divider provides equi-phase power division on two equal halves, one input of the feeding device is connected to a transmitter or a receiver and each of four outputs of the feeding device is connected correspondingly to each radiator of the four antennas, and the input and the four outputs of the feeding device are made in form of dual mode transmission lines, the input is connected with the four output with help of four dividers, central branches of the four dividers are connected to the input while side branches of each of the dividers are connected to neighboring outputs and four phase shifters with 180 degree phase shift are inserted in the side branches of the dividers connected with the outputs located at the opposite sides of the feeding device

16. The antenna-feeder device according to claim 15 further comprising sections of circular waveguide as input and output;

17. The antenna-feeder device according to claim 15 further comprising sections of square waveguide as input and output;

18. The antenna-feeder device according to claim 15 further comprising T-shaped junctions on the base of transmission lines as dividers;

19. The antenna-feeder device according to claim 15 further comprising the phase shifters realized as sections of rectangular waveguide of decreased or increased width;

20. The antenna-feeder device according to claim 15 further comprising the phase shifters realized as additional sections of transmission lines;