US-12627022-B2 - Resonator

Abstract

A resonator is described including: a first part of a metal cavity; a first ring extending from the first part of the metal cavity, wherein at least part of an external surface of the first supporting ring is coated with a first metal coating that provides an electrical connection to the metal cavity; a second part of the metal cavity; and a ceramic ring extending from the second part of the metal cavity. At least part of an external surface of the ceramic ring is coated with a second metal coating that provides an electrical connection to the metal cavity, wherein the first and second parts are mounted to form the metal cavity such that the first ring and the ceramic ring partially overlap such that at least part of the ceramic ring is between at least parts of the first and second metal coatings.

Inventors

• Efstratios Doumanis

Assignees

• NOKIA SOLUTIONS AND NETWORKS OY

Dates

Publication Date

20260512

Application Date

20211022

Priority Date

20201029

Claims (20)

1. 1 . A resonator, comprising: a first part of a metal cavity; a first ring extending from the first part of the metal cavity, wherein at least part of an external surface of the first ring is coated with a first metal coating that provides an electrical connection to the metal cavity; a second part of the metal cavity; and a ceramic ring extending from the second part of the metal cavity, wherein at least part of an external surface of the ceramic ring is coated with a second metal coating that provides an electrical connection to the metal cavity; wherein the first part of the metal cavity and the second part of the metal cavity are mounted to form the metal cavity such that the first ring and the ceramic ring partially overlap such that at least part of the ceramic ring is between at least part of the first metal coating and at least part of the second metal coating; and wherein the first ring extends to make contact with the second part of the metal cavity.
2. 2 . A resonator as claimed in claim 1 , wherein the second part further comprises a second ring extending from a distal end of the ceramic ring.
3. 3 . A resonator as claimed in claim 2 , wherein the second ring extends to make contact with the first part of the metal cavity.
4. 4 . A resonator as claimed in claim 1 , wherein the ceramic ring is hollow.
5. 5 . A resonator as claimed in claim 1 , wherein the first ring is hollow.
6. 6 . A resonator as claimed in claim 1 , wherein the first ring is plastic or alumina.
7. 7 . A resonator as claimed in claim 1 , wherein the second ring is plastic or alumina.
8. 8 . A resonator as claimed in claim 1 , wherein the first part is a lid of the metal cavity.
9. 9 . A resonator as claimed in claim 1 , wherein at least one of the first or the second metal coatings comprise silver.
10. 10 . A resonator as claimed in claim 1 , further comprising a metallic tuner.
11. 11 . A resonator as claimed in claim 10 , wherein the metallic tuner forms part of the first part of the metal cavity.
12. 12 . A resonator as claimed in claim 10 , wherein the metallic tuner forms part of the second part of the metal cavity.
13. 13 . A resonator as claimed in claim 10 , wherein a position of the metallic tuner within the cavity is adjustable.
14. 14 . A filter comprising a plurality of the resonators of claim 1 .
15. 15 . A filter as claimed in claim 14 , wherein the filter is comprised in a mobile base station.
16. 16 . A filter as claimed in claim 14 , wherein the filter is a microwave passive filter.
17. 17 . A method, comprising: forming a metal cavity with attaching a first part of the metal cavity to a second part of the metal cavity such that a first ring and a ceramic ring of the metal cavity partially overlap such that at least part of the ceramic ring is between at least part of a first metal coating and at least part of a second metal coating, wherein: the first ring extends from one of the first part of the metal cavity and the ceramic ring extends from the second part of the metal cavity, wherein the first ring extends to make contact with the second part of the metal cavity; the first ring comprises an external surface that is at least partially coated with the first metal coating, wherein, in use, the first metal coating provides an electrical connection to the metal cavity; and the ceramic ring comprises an external surface that is at least partially coated with the second metal coating, wherein, in use, the second metal coating provides an electrical connection to the metal cavity.
18. 18 . A method as claimed in claim 17 , wherein attaching the first part of the metal cavity to the second part of the metal cavity comprises sliding the first ring within the ceramic ring.
19. 19 . A method as claimed in claim 17 , further comprising forming at least one of the first part of the metal cavity or the second part of the metal cavity.
20. 20 . A method as claimed in claim 17 , wherein the first part of the metal cavity is a lid and the second part of the metal cavity is a base.

Description

CROSS REFERENCE TO RELATED APPLICATION This patent application is a U.S. National Stage application of International Patent Application Number PCT/EP2021/079398 filed Oct. 22, 2021, which is hereby incorporated by reference in its entirety, and claims priority to FI 20206078 filed Oct. 29, 2020. FIELD This present specification relates to resonators and filters, such as radio frequency resonators and filters. BACKGROUND A number of resonator configurations, such as ceramic resonators, are known. Although many resonator configurations are known, there remains a need for further developments in this field. SUMMARY In a first aspect, this specification describes a resonator comprising: a first part of a metal cavity; a first ring (e.g. a first supporting ring) extending from the first part of the metal cavity, wherein at least part of an external surface of the first ring is coated with a first metal coating (such as silver) that provides an electrical connection to the metal cavity; a second part of the metal cavity; and a ceramic ring extending from the second part of the metal cavity, wherein at least part of an external surface of the ceramic ring is coated with a second metal coating (such as silver) that provides an electrical connection to the metal cavity, wherein the first and second parts are mounted to form the metal cavity such that the first ring and the ceramic ring partially overlap such that at least part of the ceramic ring is between at least parts of the first and second metal coatings. The first ring may extend in a direction substantially perpendicular to the first part of the metal cavity. Similarly, the ceramic ring may extend in a direction substantially perpendicular to the second part of the metal cavity. The first ring extends to make contact with the second part of the metal cavity. In this way, additional mechanical support may be provided. The second part may further comprises a second ring (e.g. a second supporting ring) extending from a distal end of the ceramic ring. The second ring may extend to make contact with the first part of the metal cavity. In this way, additional mechanical support may be provided. The ceramic ring may be hollow (such as a hollow cylindrical ring). Alternatively, or in addition, the first ring may be hollow (such as a hollow cylindrical ring). The second ring (if provided) may be hollow (such as a hollow cylindrical ring). The first part of the metal cavity may be a lid of the metal cavity. The resonator may further comprise a metallic tuner. The metallic tuner may form part of the first part of the metal cavity. Alternatively, the metallic tuner may form part of the second part of the metal cavity. A position of the metallic tuner within the cavity may adjustable, for example by adjusting a screw thread. In a second aspect, this specification describes a method (e.g. a method of manufacturing a resonator) comprising: attaching a cavity lid to a cavity base to form a metal cavity such that a first ring (e.g. a first supporting ring) and a ceramic ring of the metal cavity partially overlap such that at least part of a ceramic ring is between at least parts of a first and a second metal coating, wherein: the first ring extends from one of the lid and the base and the ceramic ring extends from the other of the lid and the base; the first ring comprises an external surface that is at least partially coated with the first metal coating, wherein, in use, the first metal coating provides an electrical connection to the metal cavity; and the ceramic ring comprises an external surface that is at least partially coated with the second metal coating, wherein, in use, the second metal coating provides an electrical connection to the metal cavity. Attaching the cavity lid to the cavity base may comprise sliding the first ring within the ceramic ring. The method may further comprise forming the cavity lid and/or the cavity base. When the cavity lid is attached to the cavity base, the first ring may extend to make contact with the cavity base (or the cavity lid). Similarly, a second ring may be provided that extends from the ceramic ring to make contact with the cavity lid (or the cavity base) when the cavity lid is attached to the cavity base. The method may further comprise adjusting a position of a metallic tuner within the metal cavity. BRIEF DESCRIPTION OF THE DRAWINGS Example embodiments will now be described, by way of example only, with reference to the following schematic drawings, in which: FIG. 1 shows a resonator in accordance with an example embodiment; FIG. 2 shows the resonator of FIG. 1 without a lid; FIG. 3 shows internal elements of a resonator element in accordance with an example embodiment; FIG. 4 is a cross-section of a first part of a resonator in accordance with an example embodiment; FIG. 5 shows external elements of a resonator element in accordance with an example embodiment; FIG. 6 is a cross-section of a second part of a resonator in acc