Helical resonator filter with adjustable couplings

• US 5,157,363 A
• Filed: 02/05/1991
• Issued: 10/20/1992
• Est. Priority Date: 02/07/1990
• Status: Expired due to Fees

• Current Assignee: LK Products Oy (Yageo Corporation)
• Original Assignee: Pulse Finland Oy (Yageo Corporation)
• Inventors: Lehmus, Kai, Puurunen, Pertti
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): NOT, DEFINED
• Application Number:
  US07/650,875
• Time in Patent Office: 623 Days
• Field of Search: 333/202, 333/203, 333/219, 333/235, 333/230, 333/212, 333/180, 333/231-233
• US Class Current: 333/202
• CPC Class Codes: H01P 1/2053 the coaxial cavity resonators being disposed parall to each other

Abstract

A high-frequency filter employing helix resonators and a metallic or metallized cover. The cover contains at least two helix-shaped resonator coils separated from each other by a metallic or metallized partition provided with an aperture which there is a tuning strip, by reducing the size of which the size of the aperture can be enlarged and thereby the electrical coupling between the resonators adjusted.

Claims

1. A high frequency filter including helical resonators, the filter comprising:

a cover having at least two cavities separated by a partition having an aperture; and

a helical-shaped resonator coil disposed within each cavity;

wherein a size of the aperture serves to affect electrical coupling between the resonator coil disposed in each cavity, the partition having a tuning element extending from a first edge of the aperture parallel to the plane of the partition into the aperture, the partition and the tuning element being formed form a single piece, a length of the turning element being less than a length between the first edge of the aperture and a second edge of the aperture, the second edge being opposite the first edge of the aperture and a second edge of the aperture, the second edge being opposite the first edge, wherein a size of the turning element can be reduced to increase the size of the aperture, thereby adjusting the electrical coupling between the resonator coils.

2. The high-frequency filter according to claim 1, wherein the size of the aperture is increased by shortening the length of the tuning element, thereby changing the electrical coupling between the resonator coils.

3. The high-frequency filter according to claim 1, wherein the electrical coupling between the resonator coils can be adjusted by bending the tuning element out of parallel with the plane of the partition.

4. A multistage helical resonator filter cover comprising:

a shell member including a plurality of side walls and opposing end walls thereby defining a main cavity; and

at least one partition formed within the main cavity, thereby forming a plurality of sub-cavities for holding resonant circuits of a multistage helical resonator filter,

wherein at least one partition includes an aperture serving to affect electrical coupling between the subcavities, the aperture having a tuning element extending from a first edge of the aperture parallel to the plane of the partition into the aperture, the at least one partition and the tuning element being formed from a single piece, a length of the turning element being less than a length between the first edge of the aperture and a second edge of the aperture, the second edge being opposite the first edge, wherein a size of the turning element can be reduced to increase the size of the aperture and thereby changing the electrical coupling between the subcavities.

5. The multistage helical resonator filter cover according to claim 4, wherein the at least one partition and the turning element are coplanar.

6. The multistage helical resonator filter cover according to claim 4, wherein the size of the aperture is increased by shortening the length of tuning element, thereby changing the electrical coupling between the subcavities.

7. The multistage helical resonator filter cover according to claim 4, wherein the electrical coupling between the subcavities can be adjusted by bending the turning element out of parallel with the plane of the at least one partition.

8. The multistage helical resonator filter cover according to claim 5, wherein the electrical coupling between the subcavities can be adjusted by bending the tuning element into a plane which is not coplanar with the at least one partition.

9. A multistage helical resonator filter cover comprising:

a shell member including a plurality of side walls and opposing end walls thereby defining a main cavity; and

at least one partition formed within the main cavity, thereby forming a plurality of sub-cavities for holding resonant circuits of a multistage helical resonator filter,

wherein at least one partition includes an aperture serving to affect electrical coupling between the subcavities, the at least one partition having a turning element extending from a first edge of the aperture into the aperture parallel to the at least one partition and having a length being less than a length between the first edge of the aperture and a second edge of the aperture, the second edge being opposite the first edge, wherein a size of the tuning element can be reduced to increase the size of the aperture and thereby changing the electrical coupling between subcavities of the cover, and

wherein the electrical coupling between the subcavities can be adjusted by bending the turning element out of parallel with the plane of the at least one partition.

10. A multistage helical resonator filter cover comprising:

a shell member including a plurality of side walls and opposing end walls thereby defining a main cavity; and

at least one partition formed within the main cavity, thereby forming a plurality of sub-cavities for holding resonant circuits of a multistage helical resonator filter,

wherein at least one partition includes an aperture serving to affect electrical coupling between the subcavities, the at least one partition having a tuning element extending from a first edge of the aperture into the aperture coplanar with the at least one partition and having a length being less than a length between the first edge of the aperture and a second edge of the aperture, the second edge being opposite the first edge, wherein a size of the turning element can be reduced to increase the size of the aperture and thereby changing the electrical coupling between the subcavities of the cover, and

wherein the electrical coupling between the subcavities can be adjusted by bending the tuning element into a plane which is not coplanar with the at least one partition.