Claims
- 1. A dielectric filter, comprising:
- a dielectric block having two ends opposed to each other;
- an outer conductor disposed on an outer surface of said dielectric block;
- a plurality of resonator holes extending between said two ends of said dielectric block, each hole having a respective inner surface on which an inner conductor is provided, each inner conductor being connected to said outer conductor at one end to form a short-circuited end of the corresponding hole, and being isolated from said outer conductor at the other end to form an open-circuited end of the corresponding hole;
- at least one of said resonator holes comprising a large-sectional-area portion and a small-sectional-area portion arranged so that said at least one hole has different respective inner diameters at said open-circuited end and said short-circuited-end; and
- the cross-sectional shape of said large-sectional-area portion being an elongated shape having a longitudinal axis, said longitudinal axis being slanted with respect to a plane in which said plurality of resonator holes are arranged.
- 2. The dielectric filter according to claim 1, wherein:
- said small-sectional-area portion has a central axis which is shifted from a central axis of said large-sectional-area portion such that said small-sectional-area portion is eccentric to said large-sectional-area portion.
- 3. A method of manufacturing a dielectric filter comprising the steps of:
- forming a dielectric block having two ends opposed to each other;
- forming an outer conductor on an outer surface of said dielectric block;
- forming a plurality of resonator holes extending between said two ends of said dielectric block, each hole having a respective inner surface;
- forming a respective inner conductor on each said inner surface, each inner conductor being connected to said outer conductor at one end to form a short-circuited end of the corresponding hole, and being isolated from said outer conductor at the other end to form an open-circuited end of the corresponding hole;
- forming at least one of said resonator holes with a large-sectional-area portion and a small-sectional-area portion arranged so that said at least one hole has different respective inner diameters at said open-circuited end and said short-circuited-end;
- the cross-sectional shape of said large-sectional-area portion being an elongated shape which defines a longitudinal axis, said longitudinal axis being angled with respect to a plane in which said plurality of resonator holes are arranged;
- adjusting the self-capacitance of said at least one resonator hole and the mutual capacitance between a pair of adjacent said resonator holes including said at least one resonator hole by changing the angle of the longitudinal axis of the cross-section of the large-sectional-area portion with respect to said plane in which said plurality of resonator holes are arranged.
- 4. A method of manufacturing a dielectric filter according to claim 3, further comprising the steps of:
- forming said small-sectional-area portion with a central axis which is shifted from a central axis of said large-sectional-area portion such that said small-sectional-area portion is eccentric to said large-sectional-area portion; and
- adjusting the self-capacitance of said at least one resonator hole and the mutual capacitance between a pair of adjacent said resonator holes including said at least one resonator hole by changing the amount by which the central axis of said small-sectional-area portion is shifted from the central axis of said large-sectional-area portion.
- 5. A dielectric duplexer comprising:
- a dielectric block having two ends opposed to each other;
- an outer conductor disposed on an outer surface of said dielectric block;
- a plurality of resonator holes extending between said two ends of said dielectric block, each hole having a respective inner surface on which an inner conductor is provided, each inner conductor being connected to said outer conductor at one end to form a short-circuited end of the corresponding hole, and being isolated from said outer conductor at the other end to form an open-circuited end of the corresponding hole;
- at least one of said resonator holes comprising a large-sectional-area portion and a small-sectional-area portion arranged so that said at least one hole has different respective inner diameters at said open-circuited end and said short-circuited-end;
- the cross-sectional shape of said large-sectional-area portion being an elongated shape which defines a longitudinal axis, said longitudinal axis being slanted with respect to a plane in which said plurality of resonator holes are arranged;
- an input/output electrode, an input electrode, and an output electrode respectively provided on the outer surface of said dielectric block;
- a first group of said resonator holes being disposed between said input/output electrode and said input electrode to define a transmission filter; and
- a second group of said resonator holes being disposed between said input/output electrode and said output electrode to define a receiving filter.
- 6. A dielectric duplexer according to claim 5, wherein:
- said small-sectional-area portion has a central axis which is shifted from a central axis of said large-sectional-area portion such that said small-sectional-area portion is eccentric to said large-sectional-area portion.
- 7. A method of manufacturing a dielectric duplexer comprising the steps of:
- forming a dielectric block having two ends opposed to each other;
- forming an outer conductor on an outer surface of said dielectric block;
- forming a plurality of resonator holes extending between said two ends of said dielectric block, each hole having a respective inner surface;
- forming an inner conductor on each said inner surface, each inner conductor being connected to said outer conductor at one end to form a short-circuited end of the corresponding hole, and being isolated from said outer conductor at the other end to form an open-circuited end of the corresponding hole;
- forming at least one of said resonator holes with a large-sectional-area portion and a small-sectional-area portion arranged so that said at least one hole has different respective inner diameters at said open-circuited end and said short-circuited-end;
- the cross-sectional shape of said large-sectional-area portion being an elongated shape which defines a longitudinal axis, said longitudinal axis being angled with respect to a plane in which said plurality of resonator holes are arranged;
- forming an input/output electrode, an input electrode, and an output electrode on the outer surface of said dielectric block;
- arranging a first group of said resonator holes disposed between said input/output electrode and said input electrode to define a transmission filter;
- arranging a second group of said resonator holes disposed between said input/output electrode and said output electrode to define a receiving filter;
- adjusting the self-capacitance of said at least one resonator hole and the mutual capacitance between a pair of adjacent said resonator holes including said at least one resonator hole by changing the angle of the longitudinal axis of the cross-section of the large-sectional-area portion with respect to said plane in which said plurality of resonator holes are arranged.
- 8. A method of manufacturing the dielectric duplexer of claim 7, further comprising the steps of:
- forming said small-sectional-area portion with a central axis which is shifted from a central axis of said large-sectional-area portion such that said small-sectional-area portion is eccentric to said large-sectional-area portion; and
- adjusting the self-capacitance of said at least one resonator hole and the mutual capacitance between a pair of adjacent said resonator holes including said at least one resonator hole by changing the amount by which the central axis of said small-sectional-area portion is shifted from the central axis of said large-sectional-area portion.
- 9. A radio transceiver including a dielectric duplexer, the duplexer comprising:
- a dielectric block having two ends opposed to each other;
- an outer conductor disposed on an outer surface of said dielectric block;
- a plurality of resonator holes extending between said two ends of said dielectric block, each hole having a respective inner surface on which an inner conductor is provided, each inner conductor being connected to said outer conductor at one end to form a short-circuited end of the corresponding hole, and being isolated from said outer conductor at the other end to form an open-circuited end of the corresponding hole;
- at least one of said resonator holes comprising a large-sectional-area portion and a small-sectional-area portion arranged so that said at least one hole has different respective inner diameters at said open-circuited end and said short-circuited-end;
- the cross-sectional shape of said large-sectional-area portion being an elongated shape which defines a longitudinal axis, said longitudinal axis being slanted with respect to a plane in which said plurality of resonator holes are arranged;
- an input/output electrode, an input electrode, and an output electrode provided on the outer surface of said dielectric block;
- a first group of said resonator holes being disposed between said input/output electrode and said input electrode to define a transmission filter;
- a second group of said resonator holes being disposed between said input/output electrode and said output electrode to define a receiving filter;
- said radio transceiver further comprising:
- a transmission circuit for generating a transmission signal and being connected to said input electrode;
- a reception circuit for receiving a reception signal and being connected to said output electrode;
- an antenna terminal connected to said input/output electrode for receiving an antenna.
- 10. A radio transceiver as recited in claim 9, wherein said small-sectional-area portion has a central axis which is shifted from a central axis of said large-sectional-area portion such that said small-sectional-area portion is eccentric to said large-sectional-area portion.
- 11. A radio transceiver as in claim 10, further comprising an antenna connected to said input/output electrode via said antenna terminal.
- 12. A radio transceiver as in claim 9, further comprising an antenna connected to said input/output electrode via said antenna terminal.
Priority Claims (2)
Number |
Date |
Country |
Kind |
9-050152 |
Mar 1997 |
JPX |
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9-344747 |
Dec 1997 |
JPX |
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Parent Case Info
This is a continuation-in-part of the present inventors' commonly-assigned U.S. patent application Ser. No. 08/612,027 filed Mar. 6, 1996, now U.S. Pat. No. 5,742,214 issued Apr. 21, 1998.
US Referenced Citations (6)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0731522 |
Sep 1996 |
EPX |
9324968 |
Dec 1993 |
WOX |
Non-Patent Literature Citations (1)
Entry |
European Search Report dated Jun. 16, 1998. |
Continuation in Parts (1)
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Number |
Date |
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Parent |
612027 |
Mar 1996 |
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