Microwave Circular Polarizer

• US 20200136220A1
• Filed: 06/07/2018
• Published: 04/30/2020
• Est. Priority Date: 06/07/2017
• Status: Active Grant

• Current Assignee: Thales Alenia Space Italia SPA (Thales SA)
• Original Assignee: Thales Alenia Space Italia SPA (Thales SA)
• Inventors: Ravanelli, Rodolfo, Campana, Paolo
• Granted Patent: US 11,367,935 B2
• Time in Patent Office: Days
• CPC Class Codes: H01P 1/173 using a conductive element
• CPC Class Codes: H01P 5/024 between hollow waveguides
• CPC Class Codes: H01P 5/103 Hollow-waveguide/coaxial-line transitions

Abstract

The invention relates to a microwave circular polarizer including: a first outer conductor; a second outer conductor connected to the first outer conductor forming a first step discontinuity therewith; and a third outer conductor connected to the second outer conductor forming a second step discontinuity therewith. An inner conductor is provided which extends inside and is spaced apart from the first, second and third outer conductors. The first and second outer conductors are axially asymmetric with respect to the inner conductor, and the third outer conductor is axially symmetric with respect to the inner conductor. The microwave circular polarizer includes first and second rectangular waveguide ports in signal communication with an internal cavity through, respectively, a first rectangular aperture and a second rectangular aperture formed through the first outer conductor. The microwave circular polarizer further includes a first septum and a second septum.

Claims

1. Microwave circular polarizer (1) including:

a first outer conductor (110), which is cylindrically shaped and internally hollow;

a second outer conductor (120), which is cylindrically shaped, internally hollow, and is connected to the first outer conductor (110) forming a first step discontinuity (141) therewith; and

a third outer conductor (130), which is cylindrically shaped, internally hollow, and is connected to the second outer conductor (120) forming a second step discontinuity (142) therewith;

wherein a first longitudinal axis of the first outer conductor (110), a second longitudinal axis of the second outer conductor (120), and a third longitudinal axis of the third outer conductor (130) are parallel to one another;

said microwave circular polarizer (1) further including an inner conductor (150), which is cylindrically shaped, extends inside the first, second and third outer conductors (110, 120, 130), and is spaced apart from said first, second and third outer conductors (110, 120, 130), thereby resulting in an internal cavity being present between said inner conductor (150) and said first, second and third outer conductors (110, 120, 130);

wherein a fourth longitudinal axis of the inner conductor (150) coincides with the third longitudinal axis and is parallel to the first and second longitudinal axes, thereby resulting in an axially asymmetrical configuration of the first and second outer conductors (110, 120) with respect to the inner conductor (150), and an axially symmetrical configuration of the third outer conductor (130) with respect to said inner conductor (150);

said microwave circular polarizer (1) further including a first rectangular waveguide port (161) and a second rectangular waveguide port (162), that are;

coupled to the first outer conductor (110) externally to the internal cavity;

oriented orthogonally to the first longitudinal axis;

positioned relative to one another so as to form a 90-degree angle with respect to said first longitudinal axis; and

in signal communication with the internal cavity through, respectively, a first rectangular aperture and a second rectangular aperture formed through the first outer conductor (110);

said microwave circular polarizer (1) further including a first septum (171) and a second septum (172);

wherein said first septum (171) is arranged on the first outer conductor (110) inside the internal cavity and is positioned, relative to the first and second rectangular waveguide ports (161, 162), so as to form, with each of said first and second rectangular waveguide ports (161, 162), a respective 45-degree angle with respect to the first longitudinal axis;

and wherein the second septum (172) is arranged on the inner conductor (150) inside the internal cavity and is positioned, relative to the first and second rectangular waveguide ports (161, 162), so as to form, with each of said first and second rectangular waveguide ports (161, 162), a respective 135-degree angle with respect to the first longitudinal axis.

2. The microwave circular polarizer of claim 1, wherein the inner conductor (150) extends longitudinally inside the whole first outer conductor (110), the whole second outer conductor (120), and the whole third outer conductor (130).

3. The microwave circular polarizer of claim 1, wherein the inner conductor (150) extends longitudinally inside the whole first outer conductor (110) and the whole second outer conductor (120), and ends with a tapered end (151) inside the third outer conductor (130).

4. The microwave circular polarizer of claim 3, wherein the tapered end (151) is cone-shaped.

5. The microwave circular polarizer according to claim 1, wherein the inner conductor (150) is internally hollow, and wherein a transmission line is provided in said inner conductor (150).

6. The microwave circular polarizer according to claim 1, wherein the first outer conductor (110) has a first width perpendicularly to the first longitudinal axis, and a first length parallelly to said first longitudinal axis;

wherein the second outer conductor (120) has;

perpendicularly to the second longitudinal axis, a first width larger than the first width; and

,

parallelly to said second longitudinal axis, a second length smaller than the first length;

and wherein the third outer conductor (130) has, perpendicularly to the third longitudinal axis, a third width larger than the first and second widths.

7. The microwave circular polarizer according to claim 1, wherein the first and second rectangular waveguide ports (161, 162) have larger size parallelly to the first longitudinal axis.

8. The microwave circular polarizer according to claim 1, wherein the first and second rectangular waveguide ports (161, 162) extend, parallelly to the first longitudinal axis, along the whole first outer connector (110).

9. The microwave circular polarizer according to claim 1, wherein the first and second septa (171, 172) have a rectangular parallelepiped shape with larger size parallelly to the first longitudinal axis.

10. The microwave circular polarizer according to claim 1, wherein the first septum (171) extends, parallelly to the first longitudinal axis, inside the whole first outer connector (110);

and wherein the second septum (172) extends, parallelly to the first longitudinal axis, inside the whole first outer connector (110) and the whole second outer connector (120).

11. Microwave antenna system including the microwave circular polarizer (1) as claimed in claim 1.