High-frequency filter having a coaxial structure

• US 10,644,376 B2
• Filed: 02/05/2015
• Issued: 05/05/2020
• Est. Priority Date: 02/13/2014
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Kathrein-Werke KG. (Kathrein SE)
• Inventors: Nita, Jens, Skiebe, Martin
• Primary Examiner(s): Pascal, Robert J
• Assistant Examiner(s): Salazar, Jr., Jorge L
• Application Number:
  US15/116,697
• Publication Number:
  US 20190036195A1
• Time in Patent Office: 1,916 Days
• Field of Search: 333202, 333203, 333206, 333207, 333219, 333222, 333223, 333224, 333225, 333226, 333227
• CPC Class Codes: H01B 3/441 from alkenes
• CPC Class Codes: H01P 1/202 Coaxial filters cascaded coaxial cavities H01P1/205
• CPC Class Codes: H01P 7/04 Coaxial resonators

Abstract

The invention relates to an improved high-frequency filter having at least one coaxial resonator is characterized by, among other things, the following features: the coaxial resonator comprises an outer conductor housing (1), an outer conductor (1′) thus being formed; an inner conductor (3) is arranged in the outer conductor housing (1), which inner conductor is mechanically and galvanically connected to the outer conductor housing at one end of the inner conductor and ends in the direction of the outer conductor housing (1) or a housing cover (7) provided there that belongs to the outer conductor housing (1) at the opposite end of the inner conductor; the outer conductor housing (1) and the inner conductor (3) are made of electrically conductive material or are covered with an electrically conductive material; the end face (3a) of the inner conductor (3) and/or the additional surface (23) of the inner conductor (3) adjacent thereto is completely or partially covered with an encasing material (21), which encasing material (21) is made of a dielectric material; and the dielectric material has a relative permittivity εr that is greater than 1.2.

Claims

1. A high-frequency filter with at least one coaxial resonator comprising:

an outer conductor housing to form an outer conductor,

an inner conductor disposed in the outer conductor housing, in which the inner conductor has one side mechanically and galvanically connected to the outer conductor housing and terminates on another side space apart from the outer conductor housing or a housing cover provided at, and associated with, the outer conductor housing,

the outer conductor housing and the inner conductor consisting of, or coated with, an electrically conductive material,

an end face of the inner conductor and an adjacent other surface of the inner conductor is fully or partially covered with a sheathing material,

the sheathing material consists of a dielectric material,

the dielectric material has a dielectric constant ε

_r that is greater than 1.2,

the sheathing material consisting of, or including, the dielectric material in the form of one or several cyclic olefin copolymers (COC),

a thickness of the sheathing material being at least 0.05 mm, and

the thickness of the sheathing material being less than 3 mm.

2. The high-frequency filter according to claim 1, wherein the dielectric constant ε

_r is greater than 1.3.

3. The high-frequency filter according to claim 1, wherein the sheathing material is formed as an injection-molded part molded on and/or around the inner conductor.

4. The high-frequency filter according to claim 1, wherein the sheathing material is formed as a molded part mounted onto the inner conductor.

5. The high-frequency filter according to claim 1, wherein the sheathing material is configured in multiple parts and includes one, two, or multiple materials which is/are molded on or around the inner conductor and/or mounted thereon as a separate molded part.

6. The high-frequency filter according to claim 1, wherein the sheathing material is provided on the end face and on an outer circumference and/or at least at an axial height on an inner circumference of an inner axial hole of the inner conductor.

7. The high-frequency filter according to claim 1, wherein the inner conductor comprises on the end face an extension area that protrudes in a radial direction, in the form of a disk-shaped extension area.

8. The high-frequency filter according to claim 7, wherein the extension area has an outer diameter which corresponds to the 1.01-fold to 4-fold of the remaining outer diameter of the inner conductor.

9. The high-frequency filter according to claim 8, wherein the extension area has a slanted bevel towards its outer circumference from the outer circumference to the bottom side and/or at the transition to an inner axial hole.

10. The high-frequency filter according to claim 7, wherein the sheathing material is also provided on the bottom side of the extension area of the inner conductor.

11. The high-frequency filter according to claim 1, wherein the sheathing material is designed as a one-piece or multiple-piece molded part and mounted like a clip onto the inner conductor, which includes undercuts.

12. The high-frequency filter according to claim 1, wherein the sheathing material is equipped with at least one support which extends from the sheathing material in axial and/or radial direction and is supported, elastically, on an inner wall of the outer conductor housing and/or the housing cover.

13. The high-frequency filter according to claim 1, wherein the inner conductor and/or the sheathing material is designed in one piece and/or that less than 80% of the other surface of the inner conductor adjacent to the end face of the inner conductor is covered with the sheathing material.

14. The high-frequency filter according to claim 13, wherein the thickness of the sheathing material is more than 0.05 mm.

15. The high-frequency filter of claim 1 wherein the presence of the sheathing material increases tuning range and/or frequency deviation of the filter.

16. The high-frequency filter of claim 1 wherein the dielectric constant ε

_r is greater than 1.5.

17. The high-frequency filter of claim 1 wherein the dielectric constant ε

_r is greater than 2.

18. The high-frequency filter of claim 1 wherein the dielectric constant ε

_r is greater than 2.5.

19. The high-frequency filter of claim 1 wherein the dielectric constant ε

_r is greater than 3.