Single-block dual-passband ceramic filter useable with a transceiver

• US 4,742,562 A
• Filed: 07/02/1986
• Issued: 05/03/1988
• Est. Priority Date: 09/27/1984
• Status: Expired due to Term

• Current Assignee: CTS Corporation
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Kommrusch, Richard S.
• Primary Examiner(s): Wan, Gene
• Assistant Examiner(s): Lee, Benny T.
• Application Number:
  US06/881,567
• Time in Patent Office: 671 Days
• Field of Search: 333/202, 333/206, 333/207, 333/219, 333/222, 333/223, 333/235, 333/134, 455/73, 455/78-83, 370/30, 370/36, 370/38
• US Class Current: 455/78
• CPC Class Codes: H01P 1/2056 Comb filters or interdigital filters with metallised resonator holes in a dielectric block

Abstract

A single-block ceramic filter (100) providing both pass and stop bands couples an RF signal from transmitter (180) to an antenna (190) and an RF signal from the antenna (190) to a receiver (170). The ceramic filter (100) includes seven holes (102, 104, 106, 108, 110, 112 and 114) each having an elongated cross section and being surrounded by capacitive strips (e.g. 130, 131, 140 and 141 for hole 106), and electrodes (120, 122 and 124) coupled to receiver (170), transmitter (180) and antenna (190), respectively. A bracket (150) may be soldered to the ceramic filter (100) for holding cables coupled to the receiver, transmitter and antenna and for mounting the ceramic filter in a radio transceiver.

Claims

1. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least two holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at a predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least two holes; and

capacitive means including strips of the top surface of the dielectric means which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

2. The filter according to claim 1, wherein said first and second coupling means includes first and second electrode means disposed on the top surface of the dielectric means near, and coupled to said first and second holes, respectively.

3. The filter according to claim 2, wherein said first and second electrode means each include a portion of the top surface of the dielectric means covered with said conductive material and surrounded by another portion of the top surface which is not covered by said conductive material.

4. The filter according to claim 1, wherein said openings of said holes each have two elongated sides arranged substantially parallel to one another.

5. A filter comprising:

dielectric means comprised of a dielectric material having top, bottom and sides surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes; and

capacitive means including strips of the top surface of the dielectric means which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

6. The filter according to claim 5, wherein said first, second and third coupling means include first, second and third electrode means disposed on the top surface of the dielectric means near, and coupled to said first, second and third holes, respectively.

7. The filter according to claim 6, wherein said first, second, and third electrode means each include a portion of the top surface of the dielectric means covered with said conductive material and surrounded by another portion of the top surface which is not covered by said conductive material.

8. The filter according to claim 5, wherein said openings of said holes each have two elongated sides arranged substantially parallel to one another.

9. A filter comprising:

a dielectric block comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric block being substantially covered with a conductive material;

at least two holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least two holes; and

capacitive means including strips of the top surface of the dielectric block which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

10. A filter comprising:

a dielectric block comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric block being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes; and

capacitive means including strips of the top surface of the dielectric block which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

11. A filter for filtering an input signal from a signal source, comprising:

dielectric means comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least two holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at a predetermined distances from one another and substantially aligned with one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least two holes, said first coupling means further being coupled to the input signal and said second coupling means providing an output signal representing the filtered input signal; and

capacitive means including strips of the top surface of the dielectric means which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

12. A multi-passband filter for coupling a radio-frequency (RF) signal from a RF transmitter to an antenna and coupling another RF signal from the antenna to an RF receiver, comprising:

dielectric means comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes, said first coupling means further being coupled to the RF transmitter, said second coupling means further being coupled to the antenna, and said third coupling means further being coupled to the RF receiver; and

capacitive means including strips of the top surface of the dielectric means which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

13. (Three Times Amended) A radio transceiver comprising:

(a) a radio receiver having an input;

(b) a radio transmitter having an output;

(c) an antenna; and

(d) a multi-passband filter comprising;

dielectric means comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes, said first coupling means further being coupled to the output of the radio transmitter, said second coupling means further being coupled to the antenna, and said third coupling means further being coupled to the input of the radio receiver; and

capacitive means including strips of the top surface of the dielectric means which substantially surround each hole, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

14. (Twice Amended) A filter comprising:

a dielectric block comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric block being substantially covered with a conductive material;

a plurality of holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said plurality of holes; and

capacitive means including first and second electrode means each comprised of a conductive material covering a portion of the top surface of said dielectric block, the conductive material of said first electrode means and the conductive material of said second electrode means being coupled to the conductive material of two holes, respectively, of said plurality of holes, and the conductive material of said first electrode means and the conductive material of said second electrode means opposing one another and being separated from one another by a portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively intercoupling said two holes.

15. The filter according to claim 14, wherein said first and second coupling means includes first and second coupling electrode means disposed on the top surface of the dielectric block near, and coupled to the conductive material of said first and second holes, respectively.

16. The filter according to claim 15, wherein said first and second coupling means each includes a portion of the top surface of the dielectric block covered with said conductive material.

17. The filter according to claim 14, further including third electrode means interposed between and capacitively intercoupling said first and second electrode means.

21. The filter according to claim 15, further including third electrode means interposed between and capacitively intercoupling said first and second electrode means.

18. A filter comprising:

a dielectric block comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric block being substantially covered with a conductive material;

a plurality of holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said plurality of holes; and

capacitive means including first and second electrode means each comprised of a conductive material covering a portion of the top surface of said dielectric block, the conductive material of said first electrode means and the conductive material of said second electrode means being coupled to the conductive material of two holes, respectively, of said plurality of holes, the conductive material of said first electrode means and the conductive material of said second electrode means opposing one another and being separated from one another by a first portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively intercoupling said two holes, and the conductive material of said first electrode means opposing the conductive coating on one of the side surfaces of said dielectric block and being separated from one another by a second portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively coupling the corresponding one of said two holes to the conductive coating on said one of the side surfaces of said dielectric block.

19. The filter according to claim 18, wherein said first and second coupling means include first and second coupling electrode means disposed on the top surface of the dielectric block near, and coupled to the conductive material of said first and second holes, respectively.

20. The filter according to claim 19, wherein said first and second coupling means each include a portion of the top surface of the dielectric block covered with said conductive material.

22. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least three holes; and

capacitive means including strips of the top surface of the dielectric means which substantially surround at least two holes of said at least three holes, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

23. A multi-passband filter for coupling a radio-frequency (RF) signal from a RF transmitter to an antenna and coupling another RF signal from the antenna to an RF receiver, comprising:

a dielectric block comprised of a dielectric material having top, bottom and side surfaces, said bottom and side surfaces of the dielectric block being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes, said first coupling means further being coupled to the RF transmitter, said second coupling means further being coupled to the antenna, and said third coupling means further being coupled to the RF receiver; and

capacitive means including first and second electrode means each comprised of a conductive material covering a portion of the top surface of said dielectric block, the conductive material of said first electrode means and the conductive material of said second electrode means being coupled to the conductive material of at least two holes, respectively, of said at least three holes, and the conductive material of said first electrode means and the conductive material of said second electrode means opposing one another and being separated from one another by a portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively intercoupling said two holes.

24. A multi-passband filter for coupling a radio-frequency (RF) signal from a RF transmitter to an antenna and coupling another RF signal from the antenna to an RF receiver, comprising:

a dielectric block comprised of a dielectric material having top, bottom and side surfaces, said bottom and side surfaces of the dielectric block being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric block toward the bottom surface thereof and having openings on the top surface of the dielectric block, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes, said first coupling means further being coupled to the RF transmitter, said second coupling means further being coupled to the antenna, and said third coupling means further being coupled to the RF receiver; and

capacitive means including first and second electrode means each comprised of a conductive material covering a portion of the top surface of said dielectric block, the conductive material of said first electrode means and the conductive material of said second electrode means being coupled to the conductive material of two holes, respectively, of said at least three holes, the conductive material of said first electrode means and the conductive material of said second electrode means opposing one another and being separated from one another by a first portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively intercoupling said two holes, and the conductive material of said first electrode means opposing the conductive coating on one of the side surfaces of said dielectric block and being separated from one another by a second portion of the top surface of said dielectric block not covered by any conductive material and having a predetermined width for capacitively coupling the corresponding one of said two holes to the conductive coating on said one of the side surfaces of said dielectric block.

25. A multi-passband filter for coupling a radio-frequency (RF) signal from a RF transmitter to an antenna and coupling another RF signal from the antenna to an RF receiver, comprising:

dielectric means comprised of a dielectric material having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances relative to one another and substantially aligned with one another;

first, second and third coupling means coupled to a first hole, a second hole and a third hole, respectively, of said at least three holes, said first coupling means further being coupled to the RF transmitter, said second coupling means further being coupled to the antenna, and said third coupling means further being coupled to the RF receiver; and

capacitive means including strips of the top surface of the dielectric means that substantially surround at least two holes of said at least three holes, said strips being portions of the top surface which are not covered with said conductive material, said strips having a width for determining the capacitance thereof, and said strips between said holes including substantially sinusoidal shaped portions.

26. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric means being substantially covered with a conductive material;

a plurality of holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances from one another, and said openings each having two elongated sides arranged substantially parallel to one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said plurality of holes; and

capacitive means including first and second electrode means coupled to the conductive material of and surrounding the openings of two holes, respectively, of said plurality of holes, for capacitively intercoupling said two holes, at least one of said first and second electrode means each further being capacitively coupled to the conductive material on the side surfaces of said dielectric means.

27. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric means being substantially covered with a conductive material;

a plurality of holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said plurality of holes;

capacitive means including first and second electrode means coupled to the conductive material of and surrounding the openings of two holes, respectively, of said plurality of holes, for capacitively intercoupling said two holes, at least one of said first and second electrodes means each further being capacitively coupled to the conductive material on the side surfaces of said dielectric means; and

bracket means coupled to said dielectric means for at least partially enclosing the top surface of said dielectric means, said bracket means further including at least first and second tab means for attaching said bracket means to utilization means.

28. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances from one another and substantially aligned with one another, and said openings each having two elongated sides arranged substantially parallel to one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least three holes; and

capacitive means including first and second electrode means coupled to the conductive material of and surrounding the openings of two holes, respectively, of said at least three holes, for capacitively intercoupling said two holes, at least one of said first and second electrode means each further being capacitively coupled to the conductive material on the side surfaces of said dielectric means.

29. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said bottom and side surfaces of the dielectric means being substantially covered with a conductive material;

at least three holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at predetermined distances from one another and substantially aligned with one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least three holes;

capacitive means including first and second electrode means coupled to the conductive material of and surrounding the openings of two holes, respectively, of said at least three holes, for capacitively intercoupling said two holes, at least one of said first and second electrode means each further being capacitively coupled to the conductive material on the side surfaces of said dielectric means; and

bracket means coupled to said dielectric means for at least partially enclosing the top surface of said dielectric means, said bracket means further including at least first and second tab means for attaching said bracket means to utilization means.

30. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least two holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed at a predetermined distances from one another, and said openings each having two elongated sides arranged substantially parallel to one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least two holes; and

capacitive means for capacitively intercoupling said first and second holes, said capacitive means including strips of the top surface of the dielectric means which substantially surround each of said first and second holes, said strips being portions of the top surface which are are not covered with said conductive material, and said strips having a width for determining the capacitance thereof.

31. A filter comprising:

dielectric means comprised of a dielectric material and having top, bottom and side surfaces, said surfaces of the dielectric means being substantially covered with a conductive material;

at least two holes, having surfaces substantially covered with a conductive material, extending from the top surface of the dielectric means toward the bottom surface thereof and having openings on the top surface of the dielectric means, said openings being disposed a predetermined distances from one another;

first and second coupling means coupled to a first hole and a second hole, respectively, of said at least two holes;

capacitive means for capacitively intercoupling said first and second holes, said capacitive means including strips of the top surface of the dielectric means which substantially surround each of said first and second holes, said strips being portions of the top surface which are are not covered with said conductive material, and said strips having a width for determining the capacitance thereof; and

bracket means coupled to said dielectric means for at least partially enclosing the top surface of said dielectric means, said bracket means further including at least first and second tab means for attaching said bracket means to utilization means.