Distribution constant filter with suppression of TE11 resonance mode

• US 4,559,508 A
• Filed: 02/08/1984
• Issued: 12/17/1985
• Est. Priority Date: 02/10/1983
• Status: Expired due to Term

• Current Assignee: Murata Manufacturing Co Limited
• Original Assignee: Murata Manufacturing Co Limited
• Inventors: Nishikawa, Toshio, Yorita, Tadahiro
• Primary Examiner(s): Nussbaum, Marvin L.
• Application Number:
  US06/578,199
• Time in Patent Office: 678 Days
• Field of Search: 333/202-212, 333/219, 333/222-235, 333/245, 333/248
• US Class Current: 333/202
• CPC Class Codes: H01P 1/2056 Comb filters or interdigital filters with metallised resonator holes in a dielectric block

Abstract

An improved distribution constant type filter provided with a connecting arrangement which includes a through-opening formed in a dielectric block of the filter along a first cavity of a resonance unit at an initial stage, and a connector provided in the through-opening so that one end of the connector is electrically conducted to a conductive layer formed on part of the outer surface of the dielectric block, with the other end of the connector being connected to an external circuit to receive an input signal. The through-opening is preferably small in lateral cross section relative to the first cavity and positioned at a central portion in a widthwise direction of the dielectric block, and thus, coupling magnetic between the resonance unit and the external circuit suppresses a TE11 resonance mode in the filter.

Claims

1. A distribution constant type filter, comprising:

(A) a resonance unit including;

(1) a dielectric block member having an outer surface, and having formed therein a pair of spaced apart first cavities extending from respective locations on said outer surface, each said first cavity forming a respective first inner surface;

(2) a conductive layer formed on at least part of said outer surface of said dielectric block member and extending into each of said first cavities and covering at least a portion of each of said first inner surfaces; and

(B) connecting means for introducing an input signal into said resonance unit and withdrawing an output signal from said resonance unit, said connecting means including;

(1) an opening formed in said block member at a location adjacent to but spaced from one of said first cavities; and

(2) a connector member located in said opening and electrically shorted to said conductive layer, said connector member extending outside of said opening so that it can be connected to an external circuit, the location and dimensions of said opening being such that magnetic coupling between said resonance unit and connecting means suppresses a TE11 resonance mode in said filter.

2. A distribution constant type filter as claimed in claim 1, wherein said dielectric block member has and induction coupling degree adjusting cavity formed therein at a location between said through-opening and said one of said first cavities.

3. A distribution constant type filter as claimed in claim 2, wherein said induction coupling degree adjusting cavity extends all the way through said dielectric block member.

4. A distribution constant type filter as claimed in claim 2, wherein said induction coupling degree adjusting cavity extends only partly through said dielectric block member.

5. A distribution constant type filter as claimed in claim 1, wherein said connector is a metallic wire.

6. A distribution constant type filter as claimed in claim 1, wherein said connector member is a metallic pin.

7. A distribution constant type filter as claimed in claim 1, wherein said connector member is a central conductor of a connector.

8. A distribution constant type filter as claimed in claim 1, wherein said connector member is electrically shorted to said conductive layer formed on at least part of said outer surface of said dielectric block member through another conductive layer forming on an inner peripheral surface of said opening.

9. A distribution constant type filter as claimed in claim 1, wherein said conductive layer is formed by a single conductive layer.

10. A distribution constant type filter as claimed in claim 1, wherein said block member has a width direction and wherein said opening is positioned at a location substantially at the middle of said block member as viewed along said widthwise direction.

11. A distribution constant type filter as claimed in claim 1, wherein said opening and connector member define an input connector to said resonance unit and wherein said connecting means further includes:

(A) a second opening formed in said block member at a location adjacent to but spaced apart from the other of said first cavities; and

(B) a second connector member located in said second opening and electrically shorted to said conductive layer, said second connector member extending outside of said second opening so that it can be connected to said external circuit as an output connector, the location and dimensions of said second opening being such that magnetic coupling between said resonance unit and said output connector suppresses a TE11 resonance mode in the filter.

12. A distribution constant type filter as claimed in claim 11, wherein said block member has a width direction and wherein said second opening is positioned at a location substantially at the middle of said block member as viewed along said widthwise direction.

13. The distribution constant type filter as claimed in claim 11, wherein said second opening is small in lateral cross section relative to said pair of first cavities.

14. A distribution constant type filter as claimed in claim 1, wherein said opening has an axis which runs parallel to an axis of said one of said first cavities.

15. A distribution constant type filter as claimed in claim 1, wherein said connector member is connected to said external circuit. PG,34

16. The distribution constant type filter as claimed in claim 1, wherein said opening is small in lateral cross section relative to said pair of first cavities.

17. A distribution constant type filter which comprises a dielectric block member having an outer surface and at least one first cavity extending from said outer surface so as to form at least one first inner surface, connecting means for introducing an input signal into said block member and for producing an output signal therefrom, and conductive layers formed on at least part of said outer surface of said block member and at least part of said at least one first inner surface formed therein, thereby to constitute resonance unit means, wherein said dielectric block member has a plurality of first cavities spaced apart from one another to provide a plurality of first inner surfaces, said conductive layers extending into each of said plurality of first cavities, said dielectric block member being a substantially brick-shaped elongated element having first and second ends with an axis through the first and second ends and having first and second sides extending between the first and second ends, said plurality of first cavities being cylindrical cavities extending from said first side of said block member, the axes of said first cavities being substantially parallel to one another and substantially perpendicular to the axis of said block member, said conductive layers being of a metalized layer formed on at least part of each first cavity and the first side of the block member, said metalized layer being formed on substantially entirely the internal surface provided by each first cavity, and wherein said block member additionally has at least one second cavity positioned between two adjacent first cavities, said at least one second cavity having an axis substantially parallel to the axes of said plurality of first cavities, said connecting means including at least one through-opening formed in said dielectric block member along said first cavity of the resonance unit means at an initial and/or final stage, and a respective connector provided in each said through-opening so that one end of said connector is electrically shorted to said conductive layer formed on at least part of said outer surface of said dielectric block member, with the other end of said connector being connected to an external circuit means, said through-opening being small in lateral cross section relative to said pair of first cavities and positioned at substantially a central portion in a widthwise direction of said dielectric block member, whereby magnetic coupling between the resonance unit means and the external circuit means suppresses a TE11 resonance mode in the filter.

18. A distribution constant type filter as claimed in claim 17, wherein said conductive layer is formed by a single conductive layer.

19. A distribution constant type filter, comprising:

(A) a resonance unit including;

(1) a dielectric block member being elongated along an axis and having first and second ends located on opposite ends of said axis, said block member having formed therein;

(a) pair of spaced apart first cavities extending from respective locations on said outer surface of said dielectric block, each of said first cavities being elongated and having respective axes which are substantially perpendicular to said axis of said block member, each of said first cavities forming a respective first inner surface; and

(b) a second cavity extending from said outer surface and located between said pair of first cavities, said second cavity forming a second inner surface, said second cavity being elongated and having an axis which lies substantially perpendicular to said axis of said block member; and

(2) a conductive layer formed on at least part of said outer surface of said dielectric block member and extending into each of said first cavities and covering at least a portion of each of said first inner surfaces, said conductive layer not extending into said second cavity and said second inner surface not having any conductive material formed thereon; and

(B) connecting means for introducing an input signal into said resonance unit and withdrawing an output signal from said resonance unit, said connecting means including;

(1) a first connector located adjacent said first end of said block member and between said first end of said block member and one of said first cavities, said first connector including;

(a) a first through-opening formed in said dielectric block member at a location adjacent to but spaced from one of said first cavities; and

(b) a first connector member located in said first through-opening and electrically shorted to said conductive layer, said first connector member extending outside of said first through-opening so that it can be connected to an external circuit, the location and dimensions of said first through-opening being such that magnetic coupling between said first connector and said one of said first cavities suppresses a TE11 resonance mode in the filter; and

(2) a second connector located adjacent said second end of said dielectric block member and between said other of said first cavities and said second end, said second connector including;

(a) a second through-opening formed in said block member at a location adjacent to but spaced from said other of said first cavities; and

(b) a second connector member located in said second through-opening and electrically shorted to said conductive layer, said second connector member extending outside of said first through-opening so that it can be connected to an external circuit, the location and dimensions of said second through-opening being such that magnetic coupling between said second connector and said other of said second cavities suppresses a TE11 resonance mode in the filter.

20. A distribution constant type filter as claimed in claim 19, wherein said conductive layer is formed by a single conductive layer.

21. A distribution constant type filter as claimed in claim 19, wherein said block member has a width direction extending perpendicular to said axis and wherein said first and second through-openings are positioned at a location substantially at the middle of said block member as viewed along said widthwise direction.

22. A distribution constant type filter as claimed in claim 19, wherein said first and second through-openings have respective axes which run parallel to said axis of a respective one of said first cavities.

23. A distribution constant type filter as claimed in claim 19, wherein said block member is substantially brick-shaped.

24. A distribution constant type filter as claimed in claim 23, wherein said block member includes a top surface, a bottom surface, a front surface, a rear surface and left and right side surfaces, the plane of said left and right side surfaces defining said first and second ends, said axis of said dielectric block running parallel to said top, bottom, front and rear surfaces and running perpendicular to said left and right side surfaces.

25. A distribution constant type filter as claimed in claim 24, wherein said axes of each of said cavities and said axes of said through-openings run parallel to one another and perpendicular to said axis of said block member.

26. The distribution constant type filter as claimed in claim 19, wherein said first and second through-openings are small in lateral cross section relative to said pair of first cavities.