Tunable helical resonator

• US 5,210,510 A
• Filed: 01/22/1991
• Issued: 05/11/1993
• Est. Priority Date: 02/07/1990
• Status: Expired due to Fees

• Current Assignee: Lk-Products OY Takatie
• Original Assignee: LK Products Oy (Yageo Corporation)
• Inventors: Karsikas, Auvo
• Primary Examiner(s): Pascal, Robert J.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/644,039
• Time in Patent Office: 840 Days
• Field of Search: 333/202, 333/219, 333/235, 333/174, 333/176, 333/178, 333/253
• US Class Current: 333/219
• CPC Class Codes: H01P 7/005 Helical resonators; Spiral resonators
• CPC Class Codes: H03J 1/00 Details of adjusting, driving, indicating, or mechanical control arrangements for resonant circuits in general
• CPC Class Codes: H03J 3/08 by varying a second parameter simultaneously with the tuning, e.g. coupling bandpass filter

Abstract

The invention relates to a helix resonator used in particular in filters operating at radio frequency. In instances in which conventional procedures based on adjusting the resonance frequency are not sufficient for tuning the resonator, the procedure of the invention can be used in which the resonator is tuned by adjusting the distance of the ground plane (the wall of the resonator cover (1)) from a leg (4) of the resonator or a lead (3), usually a micro strip, with which the resonator has been connected to an external circuit or to another resonator.

Claims

1. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a covering encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a second distance between the adjusting element and the first end of the helical coil, the second distance between the adjusting element and the first end of the helical coil, the second distance being perpendicular to the longitudinal axis of the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the first end of the helical coil and protruding towards the first end.

2. A helical resonator according to claim 1, wherein a thickness of the cover at the adjusting element is less than the thickness of the cover elsewhere.

3. A helical resonator according to claim 1, wherein a location of the adjusting element is marked on the cover.

4. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end, the first end having a portion oriented parallel with a longitudinal axis of the helical coil;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover adjacent to the portion of the first end of the helical coil oriented parallel to the longitudinal axis of the helical coil which can be adjusted to vary a second distance between the adjusting element and the portion of the first end of the helical coil.

5. A helical resonator according to claim 4, wherein the adjusting element is a flange formed in the wall of the cover adjacent to the lead coupled of the helical coil.

6. A helical resonator according to claim 4, wherein the adjusting element is a depression formed in the cover adjacent to the lead coupled to the helical coil, protruding towards the lead.

7. A helical resonator according to claim 6, wherein a thickness of the cover at the adjusting element is less than the thickness of the cover elsewhere.

8. A helical resonator according to claim 6, wherein the adjusting element is a metal sheet positioned adjacent to the lead coupled to the helical coil, the second distance being between the metal sheet and the lead coupled to the helical coil and being adjustable by a screw.

9. A helical resonator according to claim 4, wherein the adjusting element is a screw penetrating the cover adjacent to the lead coupled to the helical coil, the second distance being between the screw and the lead coupled to the helical coil and being adjustable by turning said screw.

10. A helical resonator according to claim 4, wherein a location of the adjusting element is marked on the cover.

11. A helical resonator according to claim 4, wherein the adjusting element is a rod penetration adjacent to the lead coupled to the helical coil, the second distance being between the rod and the lead and being adjustable by pushing or pulling the rod.

12. A variable bandwidth helical resonator comprising:

a housing having a cavity;

a helical coil having a first end and a second end, the coil formed within the cavity of the housing so that the first end of the coil being connected to the housing;

a lead coupled to the helical coil between the first end and the second end for setting an impedance level of the resonator; and

bandwidth adjusting means for adjusting the bandwidth of the resonator formed in the housing between a point adjacent to the lead coupled to the coil and the first end of the coil and protruding into the cavity toward the coil.

13. A turnable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end, the first end having a portion oriented parallel with a longitudinal axis of the helical coil;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a second distance between the adjusting element and the first end of the helical coil, wherein the adjusting element is a flange formed in the wall of the cover adjacent to the first end of the helical coil.

14. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the first end of the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the first end of the helical coil and protruding towards the first end.

15. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the first end of the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the first end of the helical coil and protruding towards the first end, and wherein a thickness of the cover at the adjusting element is less than the thickness of the cover elsewhere.

16. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the first end of the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the first end of the helical coil and protruding towards the first end, and wherein the adjusting element is a metal sheet positioned adjacent to the first end of the helical coil, a distance between the metal sheet and the first end of the helical coil being adjustable by a screw.

17. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end, the first end having a portion oriented parallel with a longitudinal axis of the helical coil;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance form the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance second between the adjusting element and the lead coupled to the helical coil, wherein the adjusting element is a flange formed in the wall of the cover adjacent to the lead coupled of the helical coil.

18. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the lead coupled to the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the lead coupled to the helical coil, protruding towards the lead.

19. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the lead coupled to the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the lead coupled to the helical coil, protruding towards the lead, and wherein a thickness of the cover at the adjusting element is less than the thickness of the cover elsewhere.

20. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a distance from the cover; and

an adjusting element formed in the cover which can be adjusted to vary a distance between the adjusting element and the lead coupled to the helical coil, wherein the adjusting element is a depression formed in the cover adjacent to the lead coupled to the helical coil, protruding towards the lead, and wherein the adjusting element is a metal sheet positioned adjacent to the lead coupled to the helical coil, a distance between the metal sheet and the lead coupled to the helical coil being adjustable by a screw.

21. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first end and second end;

a cover encircling the helical coil, so that the fist end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover adjacent to the first end of the helical coil which can be adjusted to vary a second distance between the adjusting element and the first end of the helical coil, the second distance being perpendicular to a longitudinal axis of the helical coil, wherein the adjusting element is a metal sheet position adjacent to the first end of the helical coil, the second distance being between the metal sheet and the first end of the helical coil and being adjustable by a screw.

22. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first end and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover adjacent to the first end of the helical coil which can be adjusted to vary a second distance between the adjusting element and the first end of the helical coil, the second distance being perpendicular to a longitudinal axis of the helical coil, wherein the adjusting element is a screw penetrating the cover adjacent to the first end of the helical coil, the second distance being between the screw and the first end of the helical coil and being adjustable by turning said screw.

23. A tunable helical resonator comprising:

a helical coil having a first end, a second end and a lead coupled to the helical coil between the first end and second end;

a cover encircling the helical coil, so that the first end of said helical coil is connected to the cover and the second end being free and at a first distance from the cover; and

an adjusting element formed in the cover adjacent to the first end of the helical coil which can be adjusted to vary a second distance between the adjusting element and the first end of the helical coil, the second distance being perpendicular to a longitudinal axis of the helical coil, wherein the adjusting element is a rod penetrating the cover adjacent to the first end of the helical coil, the second distance being between the rod and the fist end of the helical coil and being adjustable by pushing or pulling the rod.